Fix: Initialize events discarded and packet lost counters to zero
[lttng-tools.git] / src / bin / lttng-sessiond / ust-app.c
CommitLineData
91d76f53
DG
1/*
2 * Copyright (C) 2011 - David Goulet <david.goulet@polymtl.ca>
bdf64013 3 * Copyright (C) 2016 - Jérémie Galarneau <jeremie.galarneau@efficios.com>
91d76f53 4 *
d14d33bf
AM
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License, version 2 only,
7 * as published by the Free Software Foundation.
91d76f53
DG
8 *
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
13 *
d14d33bf
AM
14 * You should have received a copy of the GNU General Public License along
15 * with this program; if not, write to the Free Software Foundation, Inc.,
16 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
91d76f53
DG
17 */
18
6c1c0768 19#define _LGPL_SOURCE
91d76f53 20#include <errno.h>
7972aab2 21#include <inttypes.h>
91d76f53
DG
22#include <pthread.h>
23#include <stdio.h>
24#include <stdlib.h>
099e26bd 25#include <string.h>
aba8e916
DG
26#include <sys/stat.h>
27#include <sys/types.h>
099e26bd 28#include <unistd.h>
0df502fd 29#include <urcu/compiler.h>
fb54cdbf 30#include <lttng/ust-error.h>
331744e3 31#include <signal.h>
bec39940 32
990570ed 33#include <common/common.h>
86acf0da 34#include <common/sessiond-comm/sessiond-comm.h>
1e307fab 35
7972aab2 36#include "buffer-registry.h"
86acf0da 37#include "fd-limit.h"
8782cc74 38#include "health-sessiond.h"
56fff090 39#include "ust-app.h"
48842b30 40#include "ust-consumer.h"
d80a6244 41#include "ust-ctl.h"
0b2dc8df 42#include "utils.h"
fb83fe64 43#include "session.h"
d80a6244 44
c4b88406
MD
45static
46int ust_app_flush_app_session(struct ust_app *app, struct ust_app_session *ua_sess);
47
d9bf3ca4
MD
48/* Next available channel key. Access under next_channel_key_lock. */
49static uint64_t _next_channel_key;
50static pthread_mutex_t next_channel_key_lock = PTHREAD_MUTEX_INITIALIZER;
51
52/* Next available session ID. Access under next_session_id_lock. */
53static uint64_t _next_session_id;
54static pthread_mutex_t next_session_id_lock = PTHREAD_MUTEX_INITIALIZER;
ffe60014
DG
55
56/*
d9bf3ca4 57 * Return the incremented value of next_channel_key.
ffe60014 58 */
d9bf3ca4 59static uint64_t get_next_channel_key(void)
ffe60014 60{
d9bf3ca4
MD
61 uint64_t ret;
62
63 pthread_mutex_lock(&next_channel_key_lock);
64 ret = ++_next_channel_key;
65 pthread_mutex_unlock(&next_channel_key_lock);
66 return ret;
ffe60014
DG
67}
68
69/*
7972aab2 70 * Return the atomically incremented value of next_session_id.
ffe60014 71 */
d9bf3ca4 72static uint64_t get_next_session_id(void)
ffe60014 73{
d9bf3ca4
MD
74 uint64_t ret;
75
76 pthread_mutex_lock(&next_session_id_lock);
77 ret = ++_next_session_id;
78 pthread_mutex_unlock(&next_session_id_lock);
79 return ret;
ffe60014
DG
80}
81
d65d2de8
DG
82static void copy_channel_attr_to_ustctl(
83 struct ustctl_consumer_channel_attr *attr,
84 struct lttng_ust_channel_attr *uattr)
85{
86 /* Copy event attributes since the layout is different. */
87 attr->subbuf_size = uattr->subbuf_size;
88 attr->num_subbuf = uattr->num_subbuf;
89 attr->overwrite = uattr->overwrite;
90 attr->switch_timer_interval = uattr->switch_timer_interval;
91 attr->read_timer_interval = uattr->read_timer_interval;
92 attr->output = uattr->output;
93}
94
025faf73
DG
95/*
96 * Match function for the hash table lookup.
97 *
98 * It matches an ust app event based on three attributes which are the event
99 * name, the filter bytecode and the loglevel.
100 */
18eace3b
DG
101static int ht_match_ust_app_event(struct cds_lfht_node *node, const void *_key)
102{
103 struct ust_app_event *event;
104 const struct ust_app_ht_key *key;
2106efa0 105 int ev_loglevel_value;
18eace3b
DG
106
107 assert(node);
108 assert(_key);
109
110 event = caa_container_of(node, struct ust_app_event, node.node);
111 key = _key;
2106efa0 112 ev_loglevel_value = event->attr.loglevel;
18eace3b 113
1af53eb5 114 /* Match the 4 elements of the key: name, filter, loglevel, exclusions */
18eace3b
DG
115
116 /* Event name */
117 if (strncmp(event->attr.name, key->name, sizeof(event->attr.name)) != 0) {
118 goto no_match;
119 }
120
121 /* Event loglevel. */
2106efa0 122 if (ev_loglevel_value != key->loglevel_type) {
025faf73 123 if (event->attr.loglevel_type == LTTNG_UST_LOGLEVEL_ALL
2106efa0
PP
124 && key->loglevel_type == 0 &&
125 ev_loglevel_value == -1) {
025faf73
DG
126 /*
127 * Match is accepted. This is because on event creation, the
128 * loglevel is set to -1 if the event loglevel type is ALL so 0 and
129 * -1 are accepted for this loglevel type since 0 is the one set by
130 * the API when receiving an enable event.
131 */
132 } else {
133 goto no_match;
134 }
18eace3b
DG
135 }
136
137 /* One of the filters is NULL, fail. */
138 if ((key->filter && !event->filter) || (!key->filter && event->filter)) {
139 goto no_match;
140 }
141
025faf73
DG
142 if (key->filter && event->filter) {
143 /* Both filters exists, check length followed by the bytecode. */
144 if (event->filter->len != key->filter->len ||
145 memcmp(event->filter->data, key->filter->data,
146 event->filter->len) != 0) {
147 goto no_match;
148 }
18eace3b
DG
149 }
150
1af53eb5
JI
151 /* One of the exclusions is NULL, fail. */
152 if ((key->exclusion && !event->exclusion) || (!key->exclusion && event->exclusion)) {
153 goto no_match;
154 }
155
156 if (key->exclusion && event->exclusion) {
157 /* Both exclusions exists, check count followed by the names. */
158 if (event->exclusion->count != key->exclusion->count ||
159 memcmp(event->exclusion->names, key->exclusion->names,
160 event->exclusion->count * LTTNG_UST_SYM_NAME_LEN) != 0) {
161 goto no_match;
162 }
163 }
164
165
025faf73 166 /* Match. */
18eace3b
DG
167 return 1;
168
169no_match:
170 return 0;
18eace3b
DG
171}
172
025faf73
DG
173/*
174 * Unique add of an ust app event in the given ht. This uses the custom
175 * ht_match_ust_app_event match function and the event name as hash.
176 */
d0b96690 177static void add_unique_ust_app_event(struct ust_app_channel *ua_chan,
18eace3b
DG
178 struct ust_app_event *event)
179{
180 struct cds_lfht_node *node_ptr;
181 struct ust_app_ht_key key;
d0b96690 182 struct lttng_ht *ht;
18eace3b 183
d0b96690
DG
184 assert(ua_chan);
185 assert(ua_chan->events);
18eace3b
DG
186 assert(event);
187
d0b96690 188 ht = ua_chan->events;
18eace3b
DG
189 key.name = event->attr.name;
190 key.filter = event->filter;
2106efa0 191 key.loglevel_type = event->attr.loglevel;
91c89f23 192 key.exclusion = event->exclusion;
18eace3b
DG
193
194 node_ptr = cds_lfht_add_unique(ht->ht,
195 ht->hash_fct(event->node.key, lttng_ht_seed),
196 ht_match_ust_app_event, &key, &event->node.node);
197 assert(node_ptr == &event->node.node);
198}
199
d88aee68
DG
200/*
201 * Close the notify socket from the given RCU head object. This MUST be called
202 * through a call_rcu().
203 */
204static void close_notify_sock_rcu(struct rcu_head *head)
205{
206 int ret;
207 struct ust_app_notify_sock_obj *obj =
208 caa_container_of(head, struct ust_app_notify_sock_obj, head);
209
210 /* Must have a valid fd here. */
211 assert(obj->fd >= 0);
212
213 ret = close(obj->fd);
214 if (ret) {
215 ERR("close notify sock %d RCU", obj->fd);
216 }
217 lttng_fd_put(LTTNG_FD_APPS, 1);
218
219 free(obj);
220}
221
7972aab2
DG
222/*
223 * Return the session registry according to the buffer type of the given
224 * session.
225 *
226 * A registry per UID object MUST exists before calling this function or else
227 * it assert() if not found. RCU read side lock must be acquired.
228 */
229static struct ust_registry_session *get_session_registry(
230 struct ust_app_session *ua_sess)
231{
232 struct ust_registry_session *registry = NULL;
233
234 assert(ua_sess);
235
236 switch (ua_sess->buffer_type) {
237 case LTTNG_BUFFER_PER_PID:
238 {
239 struct buffer_reg_pid *reg_pid = buffer_reg_pid_find(ua_sess->id);
240 if (!reg_pid) {
241 goto error;
242 }
243 registry = reg_pid->registry->reg.ust;
244 break;
245 }
246 case LTTNG_BUFFER_PER_UID:
247 {
248 struct buffer_reg_uid *reg_uid = buffer_reg_uid_find(
249 ua_sess->tracing_id, ua_sess->bits_per_long, ua_sess->uid);
250 if (!reg_uid) {
251 goto error;
252 }
253 registry = reg_uid->registry->reg.ust;
254 break;
255 }
256 default:
257 assert(0);
258 };
259
260error:
261 return registry;
262}
263
55cc08a6
DG
264/*
265 * Delete ust context safely. RCU read lock must be held before calling
266 * this function.
267 */
268static
fb45065e
MD
269void delete_ust_app_ctx(int sock, struct ust_app_ctx *ua_ctx,
270 struct ust_app *app)
55cc08a6 271{
ffe60014
DG
272 int ret;
273
274 assert(ua_ctx);
275
55cc08a6 276 if (ua_ctx->obj) {
fb45065e 277 pthread_mutex_lock(&app->sock_lock);
ffe60014 278 ret = ustctl_release_object(sock, ua_ctx->obj);
fb45065e 279 pthread_mutex_unlock(&app->sock_lock);
d0b96690
DG
280 if (ret < 0 && ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
281 ERR("UST app sock %d release ctx obj handle %d failed with ret %d",
282 sock, ua_ctx->obj->handle, ret);
ffe60014 283 }
55cc08a6
DG
284 free(ua_ctx->obj);
285 }
286 free(ua_ctx);
287}
288
d80a6244
DG
289/*
290 * Delete ust app event safely. RCU read lock must be held before calling
291 * this function.
292 */
8b366481 293static
fb45065e
MD
294void delete_ust_app_event(int sock, struct ust_app_event *ua_event,
295 struct ust_app *app)
d80a6244 296{
ffe60014
DG
297 int ret;
298
299 assert(ua_event);
300
53a80697 301 free(ua_event->filter);
951f0b71
JI
302 if (ua_event->exclusion != NULL)
303 free(ua_event->exclusion);
edb67388 304 if (ua_event->obj != NULL) {
fb45065e 305 pthread_mutex_lock(&app->sock_lock);
ffe60014 306 ret = ustctl_release_object(sock, ua_event->obj);
fb45065e 307 pthread_mutex_unlock(&app->sock_lock);
ffe60014
DG
308 if (ret < 0 && ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
309 ERR("UST app sock %d release event obj failed with ret %d",
310 sock, ret);
311 }
edb67388
DG
312 free(ua_event->obj);
313 }
d80a6244
DG
314 free(ua_event);
315}
316
317/*
7972aab2
DG
318 * Release ust data object of the given stream.
319 *
320 * Return 0 on success or else a negative value.
d80a6244 321 */
fb45065e
MD
322static int release_ust_app_stream(int sock, struct ust_app_stream *stream,
323 struct ust_app *app)
d80a6244 324{
7972aab2 325 int ret = 0;
ffe60014
DG
326
327 assert(stream);
328
8b366481 329 if (stream->obj) {
fb45065e 330 pthread_mutex_lock(&app->sock_lock);
ffe60014 331 ret = ustctl_release_object(sock, stream->obj);
fb45065e 332 pthread_mutex_unlock(&app->sock_lock);
ffe60014
DG
333 if (ret < 0 && ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
334 ERR("UST app sock %d release stream obj failed with ret %d",
335 sock, ret);
336 }
4063050c 337 lttng_fd_put(LTTNG_FD_APPS, 2);
8b366481
DG
338 free(stream->obj);
339 }
7972aab2
DG
340
341 return ret;
342}
343
344/*
345 * Delete ust app stream safely. RCU read lock must be held before calling
346 * this function.
347 */
348static
fb45065e
MD
349void delete_ust_app_stream(int sock, struct ust_app_stream *stream,
350 struct ust_app *app)
7972aab2
DG
351{
352 assert(stream);
353
fb45065e 354 (void) release_ust_app_stream(sock, stream, app);
84cd17c6 355 free(stream);
d80a6244
DG
356}
357
36b588ed
MD
358/*
359 * We need to execute ht_destroy outside of RCU read-side critical
0b2dc8df
MD
360 * section and outside of call_rcu thread, so we postpone its execution
361 * using ht_cleanup_push. It is simpler than to change the semantic of
362 * the many callers of delete_ust_app_session().
36b588ed
MD
363 */
364static
365void delete_ust_app_channel_rcu(struct rcu_head *head)
366{
367 struct ust_app_channel *ua_chan =
368 caa_container_of(head, struct ust_app_channel, rcu_head);
369
0b2dc8df
MD
370 ht_cleanup_push(ua_chan->ctx);
371 ht_cleanup_push(ua_chan->events);
36b588ed
MD
372 free(ua_chan);
373}
374
fb83fe64
JD
375/*
376 * Extract the lost packet or discarded events counter when the channel is
377 * being deleted and store the value in the parent channel so we can
378 * access it from lttng list and at stop/destroy.
82cac6d2
JG
379 *
380 * The session list lock must be held by the caller.
fb83fe64
JD
381 */
382static
383void save_per_pid_lost_discarded_counters(struct ust_app_channel *ua_chan)
384{
385 uint64_t discarded = 0, lost = 0;
386 struct ltt_session *session;
387 struct ltt_ust_channel *uchan;
388
389 if (ua_chan->attr.type != LTTNG_UST_CHAN_PER_CPU) {
390 return;
391 }
392
393 rcu_read_lock();
394 session = session_find_by_id(ua_chan->session->tracing_id);
d68ec974
JG
395 if (!session || !session->ust_session) {
396 /*
397 * Not finding the session is not an error because there are
398 * multiple ways the channels can be torn down.
399 *
400 * 1) The session daemon can initiate the destruction of the
401 * ust app session after receiving a destroy command or
402 * during its shutdown/teardown.
403 * 2) The application, since we are in per-pid tracing, is
404 * unregistering and tearing down its ust app session.
405 *
406 * Both paths are protected by the session list lock which
407 * ensures that the accounting of lost packets and discarded
408 * events is done exactly once. The session is then unpublished
409 * from the session list, resulting in this condition.
410 */
fb83fe64
JD
411 goto end;
412 }
413
414 if (ua_chan->attr.overwrite) {
415 consumer_get_lost_packets(ua_chan->session->tracing_id,
416 ua_chan->key, session->ust_session->consumer,
417 &lost);
418 } else {
419 consumer_get_discarded_events(ua_chan->session->tracing_id,
420 ua_chan->key, session->ust_session->consumer,
421 &discarded);
422 }
423 uchan = trace_ust_find_channel_by_name(
424 session->ust_session->domain_global.channels,
425 ua_chan->name);
426 if (!uchan) {
427 ERR("Missing UST channel to store discarded counters");
428 goto end;
429 }
430
431 uchan->per_pid_closed_app_discarded += discarded;
432 uchan->per_pid_closed_app_lost += lost;
433
434end:
435 rcu_read_unlock();
436}
437
d80a6244
DG
438/*
439 * Delete ust app channel safely. RCU read lock must be held before calling
440 * this function.
82cac6d2
JG
441 *
442 * The session list lock must be held by the caller.
d80a6244 443 */
8b366481 444static
d0b96690
DG
445void delete_ust_app_channel(int sock, struct ust_app_channel *ua_chan,
446 struct ust_app *app)
d80a6244
DG
447{
448 int ret;
bec39940 449 struct lttng_ht_iter iter;
d80a6244 450 struct ust_app_event *ua_event;
55cc08a6 451 struct ust_app_ctx *ua_ctx;
030a66fa 452 struct ust_app_stream *stream, *stmp;
7972aab2 453 struct ust_registry_session *registry;
d80a6244 454
ffe60014
DG
455 assert(ua_chan);
456
457 DBG3("UST app deleting channel %s", ua_chan->name);
458
55cc08a6 459 /* Wipe stream */
d80a6244 460 cds_list_for_each_entry_safe(stream, stmp, &ua_chan->streams.head, list) {
84cd17c6 461 cds_list_del(&stream->list);
fb45065e 462 delete_ust_app_stream(sock, stream, app);
d80a6244
DG
463 }
464
55cc08a6 465 /* Wipe context */
bec39940 466 cds_lfht_for_each_entry(ua_chan->ctx->ht, &iter.iter, ua_ctx, node.node) {
31746f93 467 cds_list_del(&ua_ctx->list);
bec39940 468 ret = lttng_ht_del(ua_chan->ctx, &iter);
55cc08a6 469 assert(!ret);
fb45065e 470 delete_ust_app_ctx(sock, ua_ctx, app);
55cc08a6 471 }
d80a6244 472
55cc08a6 473 /* Wipe events */
bec39940
DG
474 cds_lfht_for_each_entry(ua_chan->events->ht, &iter.iter, ua_event,
475 node.node) {
476 ret = lttng_ht_del(ua_chan->events, &iter);
525b0740 477 assert(!ret);
fb45065e 478 delete_ust_app_event(sock, ua_event, app);
d80a6244 479 }
edb67388 480
c8335706
MD
481 if (ua_chan->session->buffer_type == LTTNG_BUFFER_PER_PID) {
482 /* Wipe and free registry from session registry. */
483 registry = get_session_registry(ua_chan->session);
484 if (registry) {
485 ust_registry_channel_del_free(registry, ua_chan->key);
486 }
fb83fe64 487 save_per_pid_lost_discarded_counters(ua_chan);
7972aab2 488 }
d0b96690 489
edb67388 490 if (ua_chan->obj != NULL) {
d0b96690
DG
491 /* Remove channel from application UST object descriptor. */
492 iter.iter.node = &ua_chan->ust_objd_node.node;
c6e62271
DG
493 ret = lttng_ht_del(app->ust_objd, &iter);
494 assert(!ret);
fb45065e 495 pthread_mutex_lock(&app->sock_lock);
ffe60014 496 ret = ustctl_release_object(sock, ua_chan->obj);
fb45065e 497 pthread_mutex_unlock(&app->sock_lock);
ffe60014
DG
498 if (ret < 0 && ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
499 ERR("UST app sock %d release channel obj failed with ret %d",
500 sock, ret);
501 }
7972aab2 502 lttng_fd_put(LTTNG_FD_APPS, 1);
edb67388
DG
503 free(ua_chan->obj);
504 }
36b588ed 505 call_rcu(&ua_chan->rcu_head, delete_ust_app_channel_rcu);
d80a6244
DG
506}
507
fb45065e
MD
508int ust_app_register_done(struct ust_app *app)
509{
510 int ret;
511
512 pthread_mutex_lock(&app->sock_lock);
513 ret = ustctl_register_done(app->sock);
514 pthread_mutex_unlock(&app->sock_lock);
515 return ret;
516}
517
518int ust_app_release_object(struct ust_app *app, struct lttng_ust_object_data *data)
519{
520 int ret, sock;
521
522 if (app) {
523 pthread_mutex_lock(&app->sock_lock);
524 sock = app->sock;
525 } else {
526 sock = -1;
527 }
528 ret = ustctl_release_object(sock, data);
529 if (app) {
530 pthread_mutex_unlock(&app->sock_lock);
531 }
532 return ret;
533}
534
331744e3 535/*
1b532a60
DG
536 * Push metadata to consumer socket.
537 *
dc2bbdae
MD
538 * RCU read-side lock must be held to guarantee existance of socket.
539 * Must be called with the ust app session lock held.
540 * Must be called with the registry lock held.
331744e3
JD
541 *
542 * On success, return the len of metadata pushed or else a negative value.
2c57e06d
MD
543 * Returning a -EPIPE return value means we could not send the metadata,
544 * but it can be caused by recoverable errors (e.g. the application has
545 * terminated concurrently).
331744e3
JD
546 */
547ssize_t ust_app_push_metadata(struct ust_registry_session *registry,
548 struct consumer_socket *socket, int send_zero_data)
549{
550 int ret;
551 char *metadata_str = NULL;
c585821b 552 size_t len, offset, new_metadata_len_sent;
331744e3 553 ssize_t ret_val;
93ec662e 554 uint64_t metadata_key, metadata_version;
331744e3
JD
555
556 assert(registry);
557 assert(socket);
1b532a60 558
c585821b
MD
559 metadata_key = registry->metadata_key;
560
ce34fcd0 561 /*
dc2bbdae
MD
562 * Means that no metadata was assigned to the session. This can
563 * happens if no start has been done previously.
ce34fcd0 564 */
c585821b 565 if (!metadata_key) {
ce34fcd0
MD
566 return 0;
567 }
568
1b532a60 569 /*
dc2bbdae
MD
570 * On a push metadata error either the consumer is dead or the
571 * metadata channel has been destroyed because its endpoint
2c57e06d
MD
572 * might have died (e.g: relayd), or because the application has
573 * exited. If so, the metadata closed flag is set to 1 so we
574 * deny pushing metadata again which is not valid anymore on the
575 * consumer side.
1b532a60
DG
576 */
577 if (registry->metadata_closed) {
578 return -EPIPE;
579 }
331744e3 580
331744e3
JD
581 offset = registry->metadata_len_sent;
582 len = registry->metadata_len - registry->metadata_len_sent;
c585821b 583 new_metadata_len_sent = registry->metadata_len;
93ec662e 584 metadata_version = registry->metadata_version;
331744e3
JD
585 if (len == 0) {
586 DBG3("No metadata to push for metadata key %" PRIu64,
587 registry->metadata_key);
588 ret_val = len;
589 if (send_zero_data) {
590 DBG("No metadata to push");
591 goto push_data;
592 }
593 goto end;
594 }
595
596 /* Allocate only what we have to send. */
597 metadata_str = zmalloc(len);
598 if (!metadata_str) {
599 PERROR("zmalloc ust app metadata string");
600 ret_val = -ENOMEM;
601 goto error;
602 }
c585821b 603 /* Copy what we haven't sent out. */
331744e3 604 memcpy(metadata_str, registry->metadata + offset, len);
331744e3
JD
605
606push_data:
c585821b
MD
607 pthread_mutex_unlock(&registry->lock);
608 /*
609 * We need to unlock the registry while we push metadata to
610 * break a circular dependency between the consumerd metadata
611 * lock and the sessiond registry lock. Indeed, pushing metadata
612 * to the consumerd awaits that it gets pushed all the way to
613 * relayd, but doing so requires grabbing the metadata lock. If
614 * a concurrent metadata request is being performed by
615 * consumerd, this can try to grab the registry lock on the
616 * sessiond while holding the metadata lock on the consumer
617 * daemon. Those push and pull schemes are performed on two
618 * different bidirectionnal communication sockets.
619 */
620 ret = consumer_push_metadata(socket, metadata_key,
93ec662e 621 metadata_str, len, offset, metadata_version);
c585821b 622 pthread_mutex_lock(&registry->lock);
331744e3 623 if (ret < 0) {
000baf6a 624 /*
dc2bbdae
MD
625 * There is an acceptable race here between the registry
626 * metadata key assignment and the creation on the
627 * consumer. The session daemon can concurrently push
628 * metadata for this registry while being created on the
629 * consumer since the metadata key of the registry is
630 * assigned *before* it is setup to avoid the consumer
631 * to ask for metadata that could possibly be not found
632 * in the session daemon.
000baf6a 633 *
dc2bbdae
MD
634 * The metadata will get pushed either by the session
635 * being stopped or the consumer requesting metadata if
636 * that race is triggered.
000baf6a
DG
637 */
638 if (ret == -LTTCOMM_CONSUMERD_CHANNEL_FAIL) {
639 ret = 0;
c585821b
MD
640 } else {
641 ERR("Error pushing metadata to consumer");
000baf6a 642 }
331744e3
JD
643 ret_val = ret;
644 goto error_push;
c585821b
MD
645 } else {
646 /*
647 * Metadata may have been concurrently pushed, since
648 * we're not holding the registry lock while pushing to
649 * consumer. This is handled by the fact that we send
650 * the metadata content, size, and the offset at which
651 * that metadata belongs. This may arrive out of order
652 * on the consumer side, and the consumer is able to
653 * deal with overlapping fragments. The consumer
654 * supports overlapping fragments, which must be
655 * contiguous starting from offset 0. We keep the
656 * largest metadata_len_sent value of the concurrent
657 * send.
658 */
659 registry->metadata_len_sent =
660 max_t(size_t, registry->metadata_len_sent,
661 new_metadata_len_sent);
331744e3 662 }
331744e3
JD
663 free(metadata_str);
664 return len;
665
666end:
667error:
ce34fcd0
MD
668 if (ret_val) {
669 /*
dc2bbdae
MD
670 * On error, flag the registry that the metadata is
671 * closed. We were unable to push anything and this
672 * means that either the consumer is not responding or
673 * the metadata cache has been destroyed on the
674 * consumer.
ce34fcd0
MD
675 */
676 registry->metadata_closed = 1;
677 }
331744e3
JD
678error_push:
679 free(metadata_str);
680 return ret_val;
681}
682
d88aee68 683/*
ce34fcd0 684 * For a given application and session, push metadata to consumer.
331744e3
JD
685 * Either sock or consumer is required : if sock is NULL, the default
686 * socket to send the metadata is retrieved from consumer, if sock
687 * is not NULL we use it to send the metadata.
ce34fcd0 688 * RCU read-side lock must be held while calling this function,
dc2bbdae
MD
689 * therefore ensuring existance of registry. It also ensures existance
690 * of socket throughout this function.
d88aee68
DG
691 *
692 * Return 0 on success else a negative error.
2c57e06d
MD
693 * Returning a -EPIPE return value means we could not send the metadata,
694 * but it can be caused by recoverable errors (e.g. the application has
695 * terminated concurrently).
d88aee68 696 */
7972aab2
DG
697static int push_metadata(struct ust_registry_session *registry,
698 struct consumer_output *consumer)
d88aee68 699{
331744e3
JD
700 int ret_val;
701 ssize_t ret;
d88aee68
DG
702 struct consumer_socket *socket;
703
7972aab2
DG
704 assert(registry);
705 assert(consumer);
706
ce34fcd0 707 pthread_mutex_lock(&registry->lock);
ce34fcd0 708 if (registry->metadata_closed) {
dc2bbdae
MD
709 ret_val = -EPIPE;
710 goto error;
d88aee68
DG
711 }
712
d88aee68 713 /* Get consumer socket to use to push the metadata.*/
7972aab2
DG
714 socket = consumer_find_socket_by_bitness(registry->bits_per_long,
715 consumer);
d88aee68 716 if (!socket) {
331744e3 717 ret_val = -1;
ce34fcd0 718 goto error;
d88aee68
DG
719 }
720
331744e3 721 ret = ust_app_push_metadata(registry, socket, 0);
d88aee68 722 if (ret < 0) {
331744e3 723 ret_val = ret;
ce34fcd0 724 goto error;
d88aee68 725 }
dc2bbdae 726 pthread_mutex_unlock(&registry->lock);
d88aee68
DG
727 return 0;
728
ce34fcd0 729error:
dc2bbdae 730 pthread_mutex_unlock(&registry->lock);
331744e3 731 return ret_val;
d88aee68
DG
732}
733
734/*
735 * Send to the consumer a close metadata command for the given session. Once
736 * done, the metadata channel is deleted and the session metadata pointer is
dc2bbdae 737 * nullified. The session lock MUST be held unless the application is
d88aee68
DG
738 * in the destroy path.
739 *
740 * Return 0 on success else a negative value.
741 */
7972aab2
DG
742static int close_metadata(struct ust_registry_session *registry,
743 struct consumer_output *consumer)
d88aee68
DG
744{
745 int ret;
746 struct consumer_socket *socket;
747
7972aab2
DG
748 assert(registry);
749 assert(consumer);
d88aee68 750
7972aab2
DG
751 rcu_read_lock();
752
ce34fcd0
MD
753 pthread_mutex_lock(&registry->lock);
754
7972aab2 755 if (!registry->metadata_key || registry->metadata_closed) {
d88aee68 756 ret = 0;
1b532a60 757 goto end;
d88aee68
DG
758 }
759
d88aee68 760 /* Get consumer socket to use to push the metadata.*/
7972aab2
DG
761 socket = consumer_find_socket_by_bitness(registry->bits_per_long,
762 consumer);
d88aee68
DG
763 if (!socket) {
764 ret = -1;
7972aab2 765 goto error;
d88aee68
DG
766 }
767
7972aab2 768 ret = consumer_close_metadata(socket, registry->metadata_key);
d88aee68 769 if (ret < 0) {
7972aab2 770 goto error;
d88aee68
DG
771 }
772
d88aee68 773error:
1b532a60
DG
774 /*
775 * Metadata closed. Even on error this means that the consumer is not
776 * responding or not found so either way a second close should NOT be emit
777 * for this registry.
778 */
779 registry->metadata_closed = 1;
780end:
ce34fcd0 781 pthread_mutex_unlock(&registry->lock);
7972aab2 782 rcu_read_unlock();
d88aee68
DG
783 return ret;
784}
785
36b588ed
MD
786/*
787 * We need to execute ht_destroy outside of RCU read-side critical
0b2dc8df
MD
788 * section and outside of call_rcu thread, so we postpone its execution
789 * using ht_cleanup_push. It is simpler than to change the semantic of
790 * the many callers of delete_ust_app_session().
36b588ed
MD
791 */
792static
793void delete_ust_app_session_rcu(struct rcu_head *head)
794{
795 struct ust_app_session *ua_sess =
796 caa_container_of(head, struct ust_app_session, rcu_head);
797
0b2dc8df 798 ht_cleanup_push(ua_sess->channels);
36b588ed
MD
799 free(ua_sess);
800}
801
d80a6244
DG
802/*
803 * Delete ust app session safely. RCU read lock must be held before calling
804 * this function.
82cac6d2
JG
805 *
806 * The session list lock must be held by the caller.
d80a6244 807 */
8b366481 808static
d0b96690
DG
809void delete_ust_app_session(int sock, struct ust_app_session *ua_sess,
810 struct ust_app *app)
d80a6244
DG
811{
812 int ret;
bec39940 813 struct lttng_ht_iter iter;
d80a6244 814 struct ust_app_channel *ua_chan;
7972aab2 815 struct ust_registry_session *registry;
d80a6244 816
d88aee68
DG
817 assert(ua_sess);
818
1b532a60
DG
819 pthread_mutex_lock(&ua_sess->lock);
820
b161602a
MD
821 assert(!ua_sess->deleted);
822 ua_sess->deleted = true;
823
7972aab2 824 registry = get_session_registry(ua_sess);
ce34fcd0 825 if (registry) {
d88aee68 826 /* Push metadata for application before freeing the application. */
7972aab2 827 (void) push_metadata(registry, ua_sess->consumer);
d88aee68 828
7972aab2
DG
829 /*
830 * Don't ask to close metadata for global per UID buffers. Close
1b532a60
DG
831 * metadata only on destroy trace session in this case. Also, the
832 * previous push metadata could have flag the metadata registry to
833 * close so don't send a close command if closed.
7972aab2 834 */
ce34fcd0 835 if (ua_sess->buffer_type != LTTNG_BUFFER_PER_UID) {
7972aab2
DG
836 /* And ask to close it for this session registry. */
837 (void) close_metadata(registry, ua_sess->consumer);
838 }
d80a6244
DG
839 }
840
bec39940
DG
841 cds_lfht_for_each_entry(ua_sess->channels->ht, &iter.iter, ua_chan,
842 node.node) {
843 ret = lttng_ht_del(ua_sess->channels, &iter);
525b0740 844 assert(!ret);
d0b96690 845 delete_ust_app_channel(sock, ua_chan, app);
d80a6244 846 }
d80a6244 847
7972aab2
DG
848 /* In case of per PID, the registry is kept in the session. */
849 if (ua_sess->buffer_type == LTTNG_BUFFER_PER_PID) {
850 struct buffer_reg_pid *reg_pid = buffer_reg_pid_find(ua_sess->id);
851 if (reg_pid) {
852 buffer_reg_pid_remove(reg_pid);
853 buffer_reg_pid_destroy(reg_pid);
854 }
855 }
d0b96690 856
aee6bafd 857 if (ua_sess->handle != -1) {
fb45065e 858 pthread_mutex_lock(&app->sock_lock);
ffe60014 859 ret = ustctl_release_handle(sock, ua_sess->handle);
fb45065e 860 pthread_mutex_unlock(&app->sock_lock);
ffe60014
DG
861 if (ret < 0 && ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
862 ERR("UST app sock %d release session handle failed with ret %d",
863 sock, ret);
864 }
10b56aef
MD
865 /* Remove session from application UST object descriptor. */
866 iter.iter.node = &ua_sess->ust_objd_node.node;
867 ret = lttng_ht_del(app->ust_sessions_objd, &iter);
868 assert(!ret);
aee6bafd 869 }
10b56aef 870
1b532a60
DG
871 pthread_mutex_unlock(&ua_sess->lock);
872
6addfa37
MD
873 consumer_output_put(ua_sess->consumer);
874
36b588ed 875 call_rcu(&ua_sess->rcu_head, delete_ust_app_session_rcu);
d80a6244 876}
91d76f53
DG
877
878/*
284d8f55
DG
879 * Delete a traceable application structure from the global list. Never call
880 * this function outside of a call_rcu call.
36b588ed
MD
881 *
882 * RCU read side lock should _NOT_ be held when calling this function.
91d76f53 883 */
8b366481
DG
884static
885void delete_ust_app(struct ust_app *app)
91d76f53 886{
8b366481 887 int ret, sock;
d42f20df 888 struct ust_app_session *ua_sess, *tmp_ua_sess;
44d3bd01 889
82cac6d2
JG
890 /*
891 * The session list lock must be held during this function to guarantee
892 * the existence of ua_sess.
893 */
894 session_lock_list();
d80a6244 895 /* Delete ust app sessions info */
852d0037
DG
896 sock = app->sock;
897 app->sock = -1;
d80a6244 898
8b366481 899 /* Wipe sessions */
d42f20df
DG
900 cds_list_for_each_entry_safe(ua_sess, tmp_ua_sess, &app->teardown_head,
901 teardown_node) {
902 /* Free every object in the session and the session. */
36b588ed 903 rcu_read_lock();
d0b96690 904 delete_ust_app_session(sock, ua_sess, app);
36b588ed 905 rcu_read_unlock();
d80a6244 906 }
36b588ed 907
0b2dc8df 908 ht_cleanup_push(app->sessions);
10b56aef 909 ht_cleanup_push(app->ust_sessions_objd);
0b2dc8df 910 ht_cleanup_push(app->ust_objd);
d80a6244 911
6414a713 912 /*
852d0037
DG
913 * Wait until we have deleted the application from the sock hash table
914 * before closing this socket, otherwise an application could re-use the
915 * socket ID and race with the teardown, using the same hash table entry.
916 *
917 * It's OK to leave the close in call_rcu. We want it to stay unique for
918 * all RCU readers that could run concurrently with unregister app,
919 * therefore we _need_ to only close that socket after a grace period. So
920 * it should stay in this RCU callback.
921 *
922 * This close() is a very important step of the synchronization model so
923 * every modification to this function must be carefully reviewed.
6414a713 924 */
799e2c4f
MD
925 ret = close(sock);
926 if (ret) {
927 PERROR("close");
928 }
4063050c 929 lttng_fd_put(LTTNG_FD_APPS, 1);
d80a6244 930
852d0037 931 DBG2("UST app pid %d deleted", app->pid);
284d8f55 932 free(app);
82cac6d2 933 session_unlock_list();
099e26bd
DG
934}
935
936/*
f6a9efaa 937 * URCU intermediate call to delete an UST app.
099e26bd 938 */
8b366481
DG
939static
940void delete_ust_app_rcu(struct rcu_head *head)
099e26bd 941{
bec39940
DG
942 struct lttng_ht_node_ulong *node =
943 caa_container_of(head, struct lttng_ht_node_ulong, head);
f6a9efaa 944 struct ust_app *app =
852d0037 945 caa_container_of(node, struct ust_app, pid_n);
f6a9efaa 946
852d0037 947 DBG3("Call RCU deleting app PID %d", app->pid);
f6a9efaa 948 delete_ust_app(app);
099e26bd
DG
949}
950
ffe60014
DG
951/*
952 * Delete the session from the application ht and delete the data structure by
953 * freeing every object inside and releasing them.
82cac6d2
JG
954 *
955 * The session list lock must be held by the caller.
ffe60014 956 */
d0b96690 957static void destroy_app_session(struct ust_app *app,
ffe60014
DG
958 struct ust_app_session *ua_sess)
959{
960 int ret;
961 struct lttng_ht_iter iter;
962
963 assert(app);
964 assert(ua_sess);
965
966 iter.iter.node = &ua_sess->node.node;
967 ret = lttng_ht_del(app->sessions, &iter);
968 if (ret) {
969 /* Already scheduled for teardown. */
970 goto end;
971 }
972
973 /* Once deleted, free the data structure. */
d0b96690 974 delete_ust_app_session(app->sock, ua_sess, app);
ffe60014
DG
975
976end:
977 return;
978}
979
8b366481
DG
980/*
981 * Alloc new UST app session.
982 */
983static
d0b96690 984struct ust_app_session *alloc_ust_app_session(struct ust_app *app)
8b366481
DG
985{
986 struct ust_app_session *ua_sess;
987
988 /* Init most of the default value by allocating and zeroing */
989 ua_sess = zmalloc(sizeof(struct ust_app_session));
990 if (ua_sess == NULL) {
991 PERROR("malloc");
ffe60014 992 goto error_free;
8b366481
DG
993 }
994
995 ua_sess->handle = -1;
bec39940 996 ua_sess->channels = lttng_ht_new(0, LTTNG_HT_TYPE_STRING);
ad7a9107 997 ua_sess->metadata_attr.type = LTTNG_UST_CHAN_METADATA;
84ad93e8 998 pthread_mutex_init(&ua_sess->lock, NULL);
ad7a9107 999
8b366481
DG
1000 return ua_sess;
1001
ffe60014 1002error_free:
8b366481
DG
1003 return NULL;
1004}
1005
1006/*
1007 * Alloc new UST app channel.
1008 */
1009static
1010struct ust_app_channel *alloc_ust_app_channel(char *name,
d0b96690 1011 struct ust_app_session *ua_sess,
ffe60014 1012 struct lttng_ust_channel_attr *attr)
8b366481
DG
1013{
1014 struct ust_app_channel *ua_chan;
1015
1016 /* Init most of the default value by allocating and zeroing */
1017 ua_chan = zmalloc(sizeof(struct ust_app_channel));
1018 if (ua_chan == NULL) {
1019 PERROR("malloc");
1020 goto error;
1021 }
1022
1023 /* Setup channel name */
1024 strncpy(ua_chan->name, name, sizeof(ua_chan->name));
1025 ua_chan->name[sizeof(ua_chan->name) - 1] = '\0';
1026
1027 ua_chan->enabled = 1;
1028 ua_chan->handle = -1;
45893984 1029 ua_chan->session = ua_sess;
ffe60014 1030 ua_chan->key = get_next_channel_key();
bec39940
DG
1031 ua_chan->ctx = lttng_ht_new(0, LTTNG_HT_TYPE_ULONG);
1032 ua_chan->events = lttng_ht_new(0, LTTNG_HT_TYPE_STRING);
1033 lttng_ht_node_init_str(&ua_chan->node, ua_chan->name);
8b366481
DG
1034
1035 CDS_INIT_LIST_HEAD(&ua_chan->streams.head);
31746f93 1036 CDS_INIT_LIST_HEAD(&ua_chan->ctx_list);
8b366481
DG
1037
1038 /* Copy attributes */
1039 if (attr) {
ffe60014 1040 /* Translate from lttng_ust_channel to ustctl_consumer_channel_attr. */
2fe6e7f5
DG
1041 ua_chan->attr.subbuf_size = attr->subbuf_size;
1042 ua_chan->attr.num_subbuf = attr->num_subbuf;
1043 ua_chan->attr.overwrite = attr->overwrite;
1044 ua_chan->attr.switch_timer_interval = attr->switch_timer_interval;
1045 ua_chan->attr.read_timer_interval = attr->read_timer_interval;
1046 ua_chan->attr.output = attr->output;
8b366481 1047 }
ffe60014
DG
1048 /* By default, the channel is a per cpu channel. */
1049 ua_chan->attr.type = LTTNG_UST_CHAN_PER_CPU;
8b366481
DG
1050
1051 DBG3("UST app channel %s allocated", ua_chan->name);
1052
1053 return ua_chan;
1054
1055error:
1056 return NULL;
1057}
1058
37f1c236
DG
1059/*
1060 * Allocate and initialize a UST app stream.
1061 *
1062 * Return newly allocated stream pointer or NULL on error.
1063 */
ffe60014 1064struct ust_app_stream *ust_app_alloc_stream(void)
37f1c236
DG
1065{
1066 struct ust_app_stream *stream = NULL;
1067
1068 stream = zmalloc(sizeof(*stream));
1069 if (stream == NULL) {
1070 PERROR("zmalloc ust app stream");
1071 goto error;
1072 }
1073
1074 /* Zero could be a valid value for a handle so flag it to -1. */
1075 stream->handle = -1;
1076
1077error:
1078 return stream;
1079}
1080
8b366481
DG
1081/*
1082 * Alloc new UST app event.
1083 */
1084static
1085struct ust_app_event *alloc_ust_app_event(char *name,
1086 struct lttng_ust_event *attr)
1087{
1088 struct ust_app_event *ua_event;
1089
1090 /* Init most of the default value by allocating and zeroing */
1091 ua_event = zmalloc(sizeof(struct ust_app_event));
1092 if (ua_event == NULL) {
1093 PERROR("malloc");
1094 goto error;
1095 }
1096
1097 ua_event->enabled = 1;
1098 strncpy(ua_event->name, name, sizeof(ua_event->name));
1099 ua_event->name[sizeof(ua_event->name) - 1] = '\0';
bec39940 1100 lttng_ht_node_init_str(&ua_event->node, ua_event->name);
8b366481
DG
1101
1102 /* Copy attributes */
1103 if (attr) {
1104 memcpy(&ua_event->attr, attr, sizeof(ua_event->attr));
1105 }
1106
1107 DBG3("UST app event %s allocated", ua_event->name);
1108
1109 return ua_event;
1110
1111error:
1112 return NULL;
1113}
1114
1115/*
1116 * Alloc new UST app context.
1117 */
1118static
bdf64013 1119struct ust_app_ctx *alloc_ust_app_ctx(struct lttng_ust_context_attr *uctx)
8b366481
DG
1120{
1121 struct ust_app_ctx *ua_ctx;
1122
1123 ua_ctx = zmalloc(sizeof(struct ust_app_ctx));
1124 if (ua_ctx == NULL) {
1125 goto error;
1126 }
1127
31746f93
DG
1128 CDS_INIT_LIST_HEAD(&ua_ctx->list);
1129
8b366481
DG
1130 if (uctx) {
1131 memcpy(&ua_ctx->ctx, uctx, sizeof(ua_ctx->ctx));
bdf64013
JG
1132 if (uctx->ctx == LTTNG_UST_CONTEXT_APP_CONTEXT) {
1133 char *provider_name = NULL, *ctx_name = NULL;
1134
1135 provider_name = strdup(uctx->u.app_ctx.provider_name);
1136 ctx_name = strdup(uctx->u.app_ctx.ctx_name);
1137 if (!provider_name || !ctx_name) {
1138 free(provider_name);
1139 free(ctx_name);
1140 goto error;
1141 }
1142
1143 ua_ctx->ctx.u.app_ctx.provider_name = provider_name;
1144 ua_ctx->ctx.u.app_ctx.ctx_name = ctx_name;
1145 }
8b366481
DG
1146 }
1147
1148 DBG3("UST app context %d allocated", ua_ctx->ctx.ctx);
8b366481 1149 return ua_ctx;
bdf64013
JG
1150error:
1151 free(ua_ctx);
1152 return NULL;
8b366481
DG
1153}
1154
025faf73
DG
1155/*
1156 * Allocate a filter and copy the given original filter.
1157 *
1158 * Return allocated filter or NULL on error.
1159 */
51755dc8
JG
1160static struct lttng_filter_bytecode *copy_filter_bytecode(
1161 struct lttng_filter_bytecode *orig_f)
025faf73 1162{
51755dc8 1163 struct lttng_filter_bytecode *filter = NULL;
025faf73
DG
1164
1165 /* Copy filter bytecode */
1166 filter = zmalloc(sizeof(*filter) + orig_f->len);
1167 if (!filter) {
51755dc8 1168 PERROR("zmalloc alloc filter bytecode");
025faf73
DG
1169 goto error;
1170 }
1171
1172 memcpy(filter, orig_f, sizeof(*filter) + orig_f->len);
1173
1174error:
1175 return filter;
1176}
1177
51755dc8
JG
1178/*
1179 * Create a liblttng-ust filter bytecode from given bytecode.
1180 *
1181 * Return allocated filter or NULL on error.
1182 */
1183static struct lttng_ust_filter_bytecode *create_ust_bytecode_from_bytecode(
1184 struct lttng_filter_bytecode *orig_f)
1185{
1186 struct lttng_ust_filter_bytecode *filter = NULL;
1187
1188 /* Copy filter bytecode */
1189 filter = zmalloc(sizeof(*filter) + orig_f->len);
1190 if (!filter) {
1191 PERROR("zmalloc alloc ust filter bytecode");
1192 goto error;
1193 }
1194
1195 assert(sizeof(struct lttng_filter_bytecode) ==
1196 sizeof(struct lttng_ust_filter_bytecode));
1197 memcpy(filter, orig_f, sizeof(*filter) + orig_f->len);
1198error:
1199 return filter;
1200}
1201
099e26bd 1202/*
421cb601
DG
1203 * Find an ust_app using the sock and return it. RCU read side lock must be
1204 * held before calling this helper function.
099e26bd 1205 */
f20baf8e 1206struct ust_app *ust_app_find_by_sock(int sock)
099e26bd 1207{
bec39940 1208 struct lttng_ht_node_ulong *node;
bec39940 1209 struct lttng_ht_iter iter;
f6a9efaa 1210
852d0037 1211 lttng_ht_lookup(ust_app_ht_by_sock, (void *)((unsigned long) sock), &iter);
bec39940 1212 node = lttng_ht_iter_get_node_ulong(&iter);
f6a9efaa
DG
1213 if (node == NULL) {
1214 DBG2("UST app find by sock %d not found", sock);
f6a9efaa
DG
1215 goto error;
1216 }
852d0037
DG
1217
1218 return caa_container_of(node, struct ust_app, sock_n);
f6a9efaa
DG
1219
1220error:
1221 return NULL;
099e26bd
DG
1222}
1223
d0b96690
DG
1224/*
1225 * Find an ust_app using the notify sock and return it. RCU read side lock must
1226 * be held before calling this helper function.
1227 */
1228static struct ust_app *find_app_by_notify_sock(int sock)
1229{
1230 struct lttng_ht_node_ulong *node;
1231 struct lttng_ht_iter iter;
1232
1233 lttng_ht_lookup(ust_app_ht_by_notify_sock, (void *)((unsigned long) sock),
1234 &iter);
1235 node = lttng_ht_iter_get_node_ulong(&iter);
1236 if (node == NULL) {
1237 DBG2("UST app find by notify sock %d not found", sock);
1238 goto error;
1239 }
1240
1241 return caa_container_of(node, struct ust_app, notify_sock_n);
1242
1243error:
1244 return NULL;
1245}
1246
025faf73
DG
1247/*
1248 * Lookup for an ust app event based on event name, filter bytecode and the
1249 * event loglevel.
1250 *
1251 * Return an ust_app_event object or NULL on error.
1252 */
18eace3b 1253static struct ust_app_event *find_ust_app_event(struct lttng_ht *ht,
2106efa0
PP
1254 char *name, struct lttng_filter_bytecode *filter,
1255 int loglevel_value,
39c5a3a7 1256 const struct lttng_event_exclusion *exclusion)
18eace3b
DG
1257{
1258 struct lttng_ht_iter iter;
1259 struct lttng_ht_node_str *node;
1260 struct ust_app_event *event = NULL;
1261 struct ust_app_ht_key key;
18eace3b
DG
1262
1263 assert(name);
1264 assert(ht);
1265
1266 /* Setup key for event lookup. */
1267 key.name = name;
1268 key.filter = filter;
2106efa0 1269 key.loglevel_type = loglevel_value;
39c5a3a7 1270 /* lttng_event_exclusion and lttng_ust_event_exclusion structures are similar */
51755dc8 1271 key.exclusion = exclusion;
18eace3b 1272
025faf73
DG
1273 /* Lookup using the event name as hash and a custom match fct. */
1274 cds_lfht_lookup(ht->ht, ht->hash_fct((void *) name, lttng_ht_seed),
1275 ht_match_ust_app_event, &key, &iter.iter);
18eace3b
DG
1276 node = lttng_ht_iter_get_node_str(&iter);
1277 if (node == NULL) {
1278 goto end;
1279 }
1280
1281 event = caa_container_of(node, struct ust_app_event, node);
1282
1283end:
18eace3b
DG
1284 return event;
1285}
1286
55cc08a6
DG
1287/*
1288 * Create the channel context on the tracer.
d0b96690
DG
1289 *
1290 * Called with UST app session lock held.
55cc08a6
DG
1291 */
1292static
1293int create_ust_channel_context(struct ust_app_channel *ua_chan,
1294 struct ust_app_ctx *ua_ctx, struct ust_app *app)
1295{
1296 int ret;
1297
840cb59c 1298 health_code_update();
86acf0da 1299
fb45065e 1300 pthread_mutex_lock(&app->sock_lock);
852d0037 1301 ret = ustctl_add_context(app->sock, &ua_ctx->ctx,
55cc08a6 1302 ua_chan->obj, &ua_ctx->obj);
fb45065e 1303 pthread_mutex_unlock(&app->sock_lock);
55cc08a6 1304 if (ret < 0) {
ffe60014
DG
1305 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1306 ERR("UST app create channel context failed for app (pid: %d) "
1307 "with ret %d", app->pid, ret);
1308 } else {
3757b385
DG
1309 /*
1310 * This is normal behavior, an application can die during the
1311 * creation process. Don't report an error so the execution can
1312 * continue normally.
1313 */
1314 ret = 0;
ffe60014
DG
1315 DBG3("UST app disable event failed. Application is dead.");
1316 }
55cc08a6
DG
1317 goto error;
1318 }
1319
1320 ua_ctx->handle = ua_ctx->obj->handle;
1321
d0b96690
DG
1322 DBG2("UST app context handle %d created successfully for channel %s",
1323 ua_ctx->handle, ua_chan->name);
55cc08a6
DG
1324
1325error:
840cb59c 1326 health_code_update();
55cc08a6
DG
1327 return ret;
1328}
1329
53a80697
MD
1330/*
1331 * Set the filter on the tracer.
1332 */
1333static
1334int set_ust_event_filter(struct ust_app_event *ua_event,
1335 struct ust_app *app)
1336{
1337 int ret;
51755dc8 1338 struct lttng_ust_filter_bytecode *ust_bytecode = NULL;
53a80697 1339
840cb59c 1340 health_code_update();
86acf0da 1341
53a80697 1342 if (!ua_event->filter) {
86acf0da
DG
1343 ret = 0;
1344 goto error;
53a80697
MD
1345 }
1346
51755dc8
JG
1347 ust_bytecode = create_ust_bytecode_from_bytecode(ua_event->filter);
1348 if (!ust_bytecode) {
1349 ret = -LTTNG_ERR_NOMEM;
1350 goto error;
1351 }
fb45065e 1352 pthread_mutex_lock(&app->sock_lock);
51755dc8 1353 ret = ustctl_set_filter(app->sock, ust_bytecode,
53a80697 1354 ua_event->obj);
fb45065e 1355 pthread_mutex_unlock(&app->sock_lock);
53a80697 1356 if (ret < 0) {
ffe60014
DG
1357 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1358 ERR("UST app event %s filter failed for app (pid: %d) "
1359 "with ret %d", ua_event->attr.name, app->pid, ret);
1360 } else {
3757b385
DG
1361 /*
1362 * This is normal behavior, an application can die during the
1363 * creation process. Don't report an error so the execution can
1364 * continue normally.
1365 */
1366 ret = 0;
ffe60014
DG
1367 DBG3("UST app filter event failed. Application is dead.");
1368 }
53a80697
MD
1369 goto error;
1370 }
1371
1372 DBG2("UST filter set successfully for event %s", ua_event->name);
1373
1374error:
840cb59c 1375 health_code_update();
51755dc8 1376 free(ust_bytecode);
53a80697
MD
1377 return ret;
1378}
1379
51755dc8
JG
1380static
1381struct lttng_ust_event_exclusion *create_ust_exclusion_from_exclusion(
1382 struct lttng_event_exclusion *exclusion)
1383{
1384 struct lttng_ust_event_exclusion *ust_exclusion = NULL;
1385 size_t exclusion_alloc_size = sizeof(struct lttng_ust_event_exclusion) +
1386 LTTNG_UST_SYM_NAME_LEN * exclusion->count;
1387
1388 ust_exclusion = zmalloc(exclusion_alloc_size);
1389 if (!ust_exclusion) {
1390 PERROR("malloc");
1391 goto end;
1392 }
1393
1394 assert(sizeof(struct lttng_event_exclusion) ==
1395 sizeof(struct lttng_ust_event_exclusion));
1396 memcpy(ust_exclusion, exclusion, exclusion_alloc_size);
1397end:
1398 return ust_exclusion;
1399}
1400
7cc9a73c
JI
1401/*
1402 * Set event exclusions on the tracer.
1403 */
1404static
1405int set_ust_event_exclusion(struct ust_app_event *ua_event,
1406 struct ust_app *app)
1407{
1408 int ret;
51755dc8 1409 struct lttng_ust_event_exclusion *ust_exclusion = NULL;
7cc9a73c
JI
1410
1411 health_code_update();
1412
1413 if (!ua_event->exclusion || !ua_event->exclusion->count) {
1414 ret = 0;
1415 goto error;
1416 }
1417
51755dc8
JG
1418 ust_exclusion = create_ust_exclusion_from_exclusion(
1419 ua_event->exclusion);
1420 if (!ust_exclusion) {
1421 ret = -LTTNG_ERR_NOMEM;
1422 goto error;
1423 }
fb45065e 1424 pthread_mutex_lock(&app->sock_lock);
51755dc8 1425 ret = ustctl_set_exclusion(app->sock, ust_exclusion, ua_event->obj);
fb45065e 1426 pthread_mutex_unlock(&app->sock_lock);
7cc9a73c
JI
1427 if (ret < 0) {
1428 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1429 ERR("UST app event %s exclusions failed for app (pid: %d) "
1430 "with ret %d", ua_event->attr.name, app->pid, ret);
1431 } else {
1432 /*
1433 * This is normal behavior, an application can die during the
1434 * creation process. Don't report an error so the execution can
1435 * continue normally.
1436 */
1437 ret = 0;
1438 DBG3("UST app event exclusion failed. Application is dead.");
1439 }
1440 goto error;
1441 }
1442
1443 DBG2("UST exclusion set successfully for event %s", ua_event->name);
1444
1445error:
1446 health_code_update();
51755dc8 1447 free(ust_exclusion);
7cc9a73c
JI
1448 return ret;
1449}
1450
9730260e
DG
1451/*
1452 * Disable the specified event on to UST tracer for the UST session.
1453 */
1454static int disable_ust_event(struct ust_app *app,
1455 struct ust_app_session *ua_sess, struct ust_app_event *ua_event)
1456{
1457 int ret;
1458
840cb59c 1459 health_code_update();
86acf0da 1460
fb45065e 1461 pthread_mutex_lock(&app->sock_lock);
852d0037 1462 ret = ustctl_disable(app->sock, ua_event->obj);
fb45065e 1463 pthread_mutex_unlock(&app->sock_lock);
9730260e 1464 if (ret < 0) {
ffe60014
DG
1465 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1466 ERR("UST app event %s disable failed for app (pid: %d) "
1467 "and session handle %d with ret %d",
1468 ua_event->attr.name, app->pid, ua_sess->handle, ret);
1469 } else {
3757b385
DG
1470 /*
1471 * This is normal behavior, an application can die during the
1472 * creation process. Don't report an error so the execution can
1473 * continue normally.
1474 */
1475 ret = 0;
ffe60014
DG
1476 DBG3("UST app disable event failed. Application is dead.");
1477 }
9730260e
DG
1478 goto error;
1479 }
1480
1481 DBG2("UST app event %s disabled successfully for app (pid: %d)",
852d0037 1482 ua_event->attr.name, app->pid);
9730260e
DG
1483
1484error:
840cb59c 1485 health_code_update();
9730260e
DG
1486 return ret;
1487}
1488
78f0bacd
DG
1489/*
1490 * Disable the specified channel on to UST tracer for the UST session.
1491 */
1492static int disable_ust_channel(struct ust_app *app,
1493 struct ust_app_session *ua_sess, struct ust_app_channel *ua_chan)
1494{
1495 int ret;
1496
840cb59c 1497 health_code_update();
86acf0da 1498
fb45065e 1499 pthread_mutex_lock(&app->sock_lock);
852d0037 1500 ret = ustctl_disable(app->sock, ua_chan->obj);
fb45065e 1501 pthread_mutex_unlock(&app->sock_lock);
78f0bacd 1502 if (ret < 0) {
ffe60014
DG
1503 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1504 ERR("UST app channel %s disable failed for app (pid: %d) "
1505 "and session handle %d with ret %d",
1506 ua_chan->name, app->pid, ua_sess->handle, ret);
1507 } else {
3757b385
DG
1508 /*
1509 * This is normal behavior, an application can die during the
1510 * creation process. Don't report an error so the execution can
1511 * continue normally.
1512 */
1513 ret = 0;
ffe60014
DG
1514 DBG3("UST app disable channel failed. Application is dead.");
1515 }
78f0bacd
DG
1516 goto error;
1517 }
1518
78f0bacd 1519 DBG2("UST app channel %s disabled successfully for app (pid: %d)",
852d0037 1520 ua_chan->name, app->pid);
78f0bacd
DG
1521
1522error:
840cb59c 1523 health_code_update();
78f0bacd
DG
1524 return ret;
1525}
1526
1527/*
1528 * Enable the specified channel on to UST tracer for the UST session.
1529 */
1530static int enable_ust_channel(struct ust_app *app,
1531 struct ust_app_session *ua_sess, struct ust_app_channel *ua_chan)
1532{
1533 int ret;
1534
840cb59c 1535 health_code_update();
86acf0da 1536
fb45065e 1537 pthread_mutex_lock(&app->sock_lock);
852d0037 1538 ret = ustctl_enable(app->sock, ua_chan->obj);
fb45065e 1539 pthread_mutex_unlock(&app->sock_lock);
78f0bacd 1540 if (ret < 0) {
ffe60014
DG
1541 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1542 ERR("UST app channel %s enable failed for app (pid: %d) "
1543 "and session handle %d with ret %d",
1544 ua_chan->name, app->pid, ua_sess->handle, ret);
1545 } else {
3757b385
DG
1546 /*
1547 * This is normal behavior, an application can die during the
1548 * creation process. Don't report an error so the execution can
1549 * continue normally.
1550 */
1551 ret = 0;
ffe60014
DG
1552 DBG3("UST app enable channel failed. Application is dead.");
1553 }
78f0bacd
DG
1554 goto error;
1555 }
1556
1557 ua_chan->enabled = 1;
1558
1559 DBG2("UST app channel %s enabled successfully for app (pid: %d)",
852d0037 1560 ua_chan->name, app->pid);
78f0bacd
DG
1561
1562error:
840cb59c 1563 health_code_update();
78f0bacd
DG
1564 return ret;
1565}
1566
edb67388
DG
1567/*
1568 * Enable the specified event on to UST tracer for the UST session.
1569 */
1570static int enable_ust_event(struct ust_app *app,
1571 struct ust_app_session *ua_sess, struct ust_app_event *ua_event)
1572{
1573 int ret;
1574
840cb59c 1575 health_code_update();
86acf0da 1576
fb45065e 1577 pthread_mutex_lock(&app->sock_lock);
852d0037 1578 ret = ustctl_enable(app->sock, ua_event->obj);
fb45065e 1579 pthread_mutex_unlock(&app->sock_lock);
edb67388 1580 if (ret < 0) {
ffe60014
DG
1581 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1582 ERR("UST app event %s enable failed for app (pid: %d) "
1583 "and session handle %d with ret %d",
1584 ua_event->attr.name, app->pid, ua_sess->handle, ret);
1585 } else {
3757b385
DG
1586 /*
1587 * This is normal behavior, an application can die during the
1588 * creation process. Don't report an error so the execution can
1589 * continue normally.
1590 */
1591 ret = 0;
ffe60014
DG
1592 DBG3("UST app enable event failed. Application is dead.");
1593 }
edb67388
DG
1594 goto error;
1595 }
1596
1597 DBG2("UST app event %s enabled successfully for app (pid: %d)",
852d0037 1598 ua_event->attr.name, app->pid);
edb67388
DG
1599
1600error:
840cb59c 1601 health_code_update();
edb67388
DG
1602 return ret;
1603}
1604
099e26bd 1605/*
7972aab2 1606 * Send channel and stream buffer to application.
4f3ab6ee 1607 *
ffe60014 1608 * Return 0 on success. On error, a negative value is returned.
4f3ab6ee 1609 */
7972aab2
DG
1610static int send_channel_pid_to_ust(struct ust_app *app,
1611 struct ust_app_session *ua_sess, struct ust_app_channel *ua_chan)
4f3ab6ee
DG
1612{
1613 int ret;
ffe60014 1614 struct ust_app_stream *stream, *stmp;
4f3ab6ee
DG
1615
1616 assert(app);
ffe60014 1617 assert(ua_sess);
4f3ab6ee 1618 assert(ua_chan);
4f3ab6ee 1619
840cb59c 1620 health_code_update();
4f3ab6ee 1621
7972aab2
DG
1622 DBG("UST app sending channel %s to UST app sock %d", ua_chan->name,
1623 app->sock);
86acf0da 1624
ffe60014
DG
1625 /* Send channel to the application. */
1626 ret = ust_consumer_send_channel_to_ust(app, ua_sess, ua_chan);
a7169585
MD
1627 if (ret == -EPIPE || ret == -LTTNG_UST_ERR_EXITING) {
1628 ret = -ENOTCONN; /* Caused by app exiting. */
1629 goto error;
1630 } else if (ret < 0) {
b551a063
DG
1631 goto error;
1632 }
1633
d88aee68
DG
1634 health_code_update();
1635
ffe60014
DG
1636 /* Send all streams to application. */
1637 cds_list_for_each_entry_safe(stream, stmp, &ua_chan->streams.head, list) {
1638 ret = ust_consumer_send_stream_to_ust(app, ua_chan, stream);
a7169585
MD
1639 if (ret == -EPIPE || ret == -LTTNG_UST_ERR_EXITING) {
1640 ret = -ENOTCONN; /* Caused by app exiting. */
1641 goto error;
1642 } else if (ret < 0) {
ffe60014
DG
1643 goto error;
1644 }
1645 /* We don't need the stream anymore once sent to the tracer. */
1646 cds_list_del(&stream->list);
fb45065e 1647 delete_ust_app_stream(-1, stream, app);
ffe60014 1648 }
ffe60014
DG
1649 /* Flag the channel that it is sent to the application. */
1650 ua_chan->is_sent = 1;
ffe60014 1651
b551a063 1652error:
840cb59c 1653 health_code_update();
b551a063
DG
1654 return ret;
1655}
1656
91d76f53 1657/*
5b4a0ec0 1658 * Create the specified event onto the UST tracer for a UST session.
d0b96690
DG
1659 *
1660 * Should be called with session mutex held.
91d76f53 1661 */
edb67388
DG
1662static
1663int create_ust_event(struct ust_app *app, struct ust_app_session *ua_sess,
1664 struct ust_app_channel *ua_chan, struct ust_app_event *ua_event)
91d76f53 1665{
5b4a0ec0 1666 int ret = 0;
284d8f55 1667
840cb59c 1668 health_code_update();
86acf0da 1669
5b4a0ec0 1670 /* Create UST event on tracer */
fb45065e 1671 pthread_mutex_lock(&app->sock_lock);
852d0037 1672 ret = ustctl_create_event(app->sock, &ua_event->attr, ua_chan->obj,
5b4a0ec0 1673 &ua_event->obj);
fb45065e 1674 pthread_mutex_unlock(&app->sock_lock);
5b4a0ec0 1675 if (ret < 0) {
ffe60014
DG
1676 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
1677 ERR("Error ustctl create event %s for app pid: %d with ret %d",
1678 ua_event->attr.name, app->pid, ret);
1679 } else {
3757b385
DG
1680 /*
1681 * This is normal behavior, an application can die during the
1682 * creation process. Don't report an error so the execution can
1683 * continue normally.
1684 */
1685 ret = 0;
ffe60014
DG
1686 DBG3("UST app create event failed. Application is dead.");
1687 }
5b4a0ec0 1688 goto error;
91d76f53 1689 }
f6a9efaa 1690
5b4a0ec0 1691 ua_event->handle = ua_event->obj->handle;
284d8f55 1692
5b4a0ec0 1693 DBG2("UST app event %s created successfully for pid:%d",
852d0037 1694 ua_event->attr.name, app->pid);
f6a9efaa 1695
840cb59c 1696 health_code_update();
86acf0da 1697
025faf73
DG
1698 /* Set filter if one is present. */
1699 if (ua_event->filter) {
1700 ret = set_ust_event_filter(ua_event, app);
1701 if (ret < 0) {
1702 goto error;
1703 }
1704 }
1705
7cc9a73c
JI
1706 /* Set exclusions for the event */
1707 if (ua_event->exclusion) {
1708 ret = set_ust_event_exclusion(ua_event, app);
1709 if (ret < 0) {
1710 goto error;
1711 }
1712 }
1713
8535a6d9 1714 /* If event not enabled, disable it on the tracer */
40113787
MD
1715 if (ua_event->enabled) {
1716 /*
1717 * We now need to explicitly enable the event, since it
1718 * is now disabled at creation.
1719 */
1720 ret = enable_ust_event(app, ua_sess, ua_event);
1721 if (ret < 0) {
1722 /*
1723 * If we hit an EPERM, something is wrong with our enable call. If
1724 * we get an EEXIST, there is a problem on the tracer side since we
1725 * just created it.
1726 */
1727 switch (ret) {
1728 case -LTTNG_UST_ERR_PERM:
1729 /* Code flow problem */
1730 assert(0);
1731 case -LTTNG_UST_ERR_EXIST:
1732 /* It's OK for our use case. */
1733 ret = 0;
1734 break;
1735 default:
1736 break;
1737 }
1738 goto error;
1739 }
8535a6d9
DG
1740 }
1741
5b4a0ec0 1742error:
840cb59c 1743 health_code_update();
5b4a0ec0 1744 return ret;
91d76f53 1745}
48842b30 1746
5b4a0ec0
DG
1747/*
1748 * Copy data between an UST app event and a LTT event.
1749 */
421cb601 1750static void shadow_copy_event(struct ust_app_event *ua_event,
48842b30
DG
1751 struct ltt_ust_event *uevent)
1752{
b4ffad32
JI
1753 size_t exclusion_alloc_size;
1754
48842b30
DG
1755 strncpy(ua_event->name, uevent->attr.name, sizeof(ua_event->name));
1756 ua_event->name[sizeof(ua_event->name) - 1] = '\0';
1757
fc34caaa
DG
1758 ua_event->enabled = uevent->enabled;
1759
5b4a0ec0
DG
1760 /* Copy event attributes */
1761 memcpy(&ua_event->attr, &uevent->attr, sizeof(ua_event->attr));
1762
53a80697
MD
1763 /* Copy filter bytecode */
1764 if (uevent->filter) {
51755dc8 1765 ua_event->filter = copy_filter_bytecode(uevent->filter);
025faf73 1766 /* Filter might be NULL here in case of ENONEM. */
53a80697 1767 }
b4ffad32
JI
1768
1769 /* Copy exclusion data */
1770 if (uevent->exclusion) {
51755dc8 1771 exclusion_alloc_size = sizeof(struct lttng_event_exclusion) +
b4ffad32
JI
1772 LTTNG_UST_SYM_NAME_LEN * uevent->exclusion->count;
1773 ua_event->exclusion = zmalloc(exclusion_alloc_size);
5f8df26c
JI
1774 if (ua_event->exclusion == NULL) {
1775 PERROR("malloc");
1776 } else {
1777 memcpy(ua_event->exclusion, uevent->exclusion,
1778 exclusion_alloc_size);
b4ffad32
JI
1779 }
1780 }
48842b30
DG
1781}
1782
5b4a0ec0
DG
1783/*
1784 * Copy data between an UST app channel and a LTT channel.
1785 */
421cb601 1786static void shadow_copy_channel(struct ust_app_channel *ua_chan,
48842b30
DG
1787 struct ltt_ust_channel *uchan)
1788{
bec39940 1789 struct lttng_ht_iter iter;
48842b30 1790 struct ltt_ust_event *uevent;
55cc08a6 1791 struct ltt_ust_context *uctx;
48842b30
DG
1792 struct ust_app_event *ua_event;
1793
fc34caaa 1794 DBG2("UST app shadow copy of channel %s started", ua_chan->name);
48842b30
DG
1795
1796 strncpy(ua_chan->name, uchan->name, sizeof(ua_chan->name));
1797 ua_chan->name[sizeof(ua_chan->name) - 1] = '\0';
ffe60014 1798
1624d5b7
JD
1799 ua_chan->tracefile_size = uchan->tracefile_size;
1800 ua_chan->tracefile_count = uchan->tracefile_count;
1801
ffe60014
DG
1802 /* Copy event attributes since the layout is different. */
1803 ua_chan->attr.subbuf_size = uchan->attr.subbuf_size;
1804 ua_chan->attr.num_subbuf = uchan->attr.num_subbuf;
1805 ua_chan->attr.overwrite = uchan->attr.overwrite;
1806 ua_chan->attr.switch_timer_interval = uchan->attr.switch_timer_interval;
1807 ua_chan->attr.read_timer_interval = uchan->attr.read_timer_interval;
1808 ua_chan->attr.output = uchan->attr.output;
1809 /*
1810 * Note that the attribute channel type is not set since the channel on the
1811 * tracing registry side does not have this information.
1812 */
48842b30 1813
fc34caaa 1814 ua_chan->enabled = uchan->enabled;
7972aab2 1815 ua_chan->tracing_channel_id = uchan->id;
fc34caaa 1816
31746f93 1817 cds_list_for_each_entry(uctx, &uchan->ctx_list, list) {
bdf64013
JG
1818 struct ust_app_ctx *ua_ctx = alloc_ust_app_ctx(&uctx->ctx);
1819
55cc08a6
DG
1820 if (ua_ctx == NULL) {
1821 continue;
1822 }
bec39940
DG
1823 lttng_ht_node_init_ulong(&ua_ctx->node,
1824 (unsigned long) ua_ctx->ctx.ctx);
aa3514e9 1825 lttng_ht_add_ulong(ua_chan->ctx, &ua_ctx->node);
31746f93 1826 cds_list_add_tail(&ua_ctx->list, &ua_chan->ctx_list);
55cc08a6 1827 }
48842b30 1828
421cb601 1829 /* Copy all events from ltt ust channel to ust app channel */
bec39940 1830 cds_lfht_for_each_entry(uchan->events->ht, &iter.iter, uevent, node.node) {
18eace3b 1831 ua_event = find_ust_app_event(ua_chan->events, uevent->attr.name,
39c5a3a7 1832 uevent->filter, uevent->attr.loglevel, uevent->exclusion);
18eace3b 1833 if (ua_event == NULL) {
421cb601 1834 DBG2("UST event %s not found on shadow copy channel",
48842b30 1835 uevent->attr.name);
284d8f55 1836 ua_event = alloc_ust_app_event(uevent->attr.name, &uevent->attr);
48842b30 1837 if (ua_event == NULL) {
5b4a0ec0 1838 continue;
48842b30 1839 }
421cb601 1840 shadow_copy_event(ua_event, uevent);
d0b96690 1841 add_unique_ust_app_event(ua_chan, ua_event);
48842b30 1842 }
48842b30
DG
1843 }
1844
fc34caaa 1845 DBG3("UST app shadow copy of channel %s done", ua_chan->name);
48842b30
DG
1846}
1847
5b4a0ec0
DG
1848/*
1849 * Copy data between a UST app session and a regular LTT session.
1850 */
421cb601 1851static void shadow_copy_session(struct ust_app_session *ua_sess,
bec39940 1852 struct ltt_ust_session *usess, struct ust_app *app)
48842b30 1853{
bec39940
DG
1854 struct lttng_ht_node_str *ua_chan_node;
1855 struct lttng_ht_iter iter;
48842b30
DG
1856 struct ltt_ust_channel *uchan;
1857 struct ust_app_channel *ua_chan;
477d7741
MD
1858 time_t rawtime;
1859 struct tm *timeinfo;
1860 char datetime[16];
1861 int ret;
d7ba1388 1862 char tmp_shm_path[PATH_MAX];
477d7741
MD
1863
1864 /* Get date and time for unique app path */
1865 time(&rawtime);
1866 timeinfo = localtime(&rawtime);
1867 strftime(datetime, sizeof(datetime), "%Y%m%d-%H%M%S", timeinfo);
48842b30 1868
421cb601 1869 DBG2("Shadow copy of session handle %d", ua_sess->handle);
48842b30 1870
7972aab2
DG
1871 ua_sess->tracing_id = usess->id;
1872 ua_sess->id = get_next_session_id();
1873 ua_sess->uid = app->uid;
1874 ua_sess->gid = app->gid;
1875 ua_sess->euid = usess->uid;
1876 ua_sess->egid = usess->gid;
1877 ua_sess->buffer_type = usess->buffer_type;
1878 ua_sess->bits_per_long = app->bits_per_long;
6addfa37 1879
7972aab2 1880 /* There is only one consumer object per session possible. */
6addfa37 1881 consumer_output_get(usess->consumer);
7972aab2 1882 ua_sess->consumer = usess->consumer;
6addfa37 1883
2bba9e53 1884 ua_sess->output_traces = usess->output_traces;
ecc48a90 1885 ua_sess->live_timer_interval = usess->live_timer_interval;
84ad93e8
DG
1886 copy_channel_attr_to_ustctl(&ua_sess->metadata_attr,
1887 &usess->metadata_attr);
7972aab2
DG
1888
1889 switch (ua_sess->buffer_type) {
1890 case LTTNG_BUFFER_PER_PID:
1891 ret = snprintf(ua_sess->path, sizeof(ua_sess->path),
dec56f6c 1892 DEFAULT_UST_TRACE_PID_PATH "/%s-%d-%s", app->name, app->pid,
7972aab2
DG
1893 datetime);
1894 break;
1895 case LTTNG_BUFFER_PER_UID:
1896 ret = snprintf(ua_sess->path, sizeof(ua_sess->path),
1897 DEFAULT_UST_TRACE_UID_PATH, ua_sess->uid, app->bits_per_long);
1898 break;
1899 default:
1900 assert(0);
1901 goto error;
1902 }
477d7741
MD
1903 if (ret < 0) {
1904 PERROR("asprintf UST shadow copy session");
477d7741 1905 assert(0);
7972aab2 1906 goto error;
477d7741
MD
1907 }
1908
3d071855
MD
1909 strncpy(ua_sess->root_shm_path, usess->root_shm_path,
1910 sizeof(ua_sess->root_shm_path));
1911 ua_sess->root_shm_path[sizeof(ua_sess->root_shm_path) - 1] = '\0';
d7ba1388
MD
1912 strncpy(ua_sess->shm_path, usess->shm_path,
1913 sizeof(ua_sess->shm_path));
1914 ua_sess->shm_path[sizeof(ua_sess->shm_path) - 1] = '\0';
1915 if (ua_sess->shm_path[0]) {
1916 switch (ua_sess->buffer_type) {
1917 case LTTNG_BUFFER_PER_PID:
1918 ret = snprintf(tmp_shm_path, sizeof(tmp_shm_path),
1919 DEFAULT_UST_TRACE_PID_PATH "/%s-%d-%s",
1920 app->name, app->pid, datetime);
1921 break;
1922 case LTTNG_BUFFER_PER_UID:
1923 ret = snprintf(tmp_shm_path, sizeof(tmp_shm_path),
1924 DEFAULT_UST_TRACE_UID_PATH,
1925 app->uid, app->bits_per_long);
1926 break;
1927 default:
1928 assert(0);
1929 goto error;
1930 }
1931 if (ret < 0) {
1932 PERROR("sprintf UST shadow copy session");
1933 assert(0);
1934 goto error;
1935 }
1936 strncat(ua_sess->shm_path, tmp_shm_path,
1937 sizeof(ua_sess->shm_path) - strlen(ua_sess->shm_path) - 1);
1938 ua_sess->shm_path[sizeof(ua_sess->shm_path) - 1] = '\0';
1939 }
1940
48842b30 1941 /* Iterate over all channels in global domain. */
bec39940
DG
1942 cds_lfht_for_each_entry(usess->domain_global.channels->ht, &iter.iter,
1943 uchan, node.node) {
1944 struct lttng_ht_iter uiter;
ba767faf 1945
bec39940
DG
1946 lttng_ht_lookup(ua_sess->channels, (void *)uchan->name, &uiter);
1947 ua_chan_node = lttng_ht_iter_get_node_str(&uiter);
5b4a0ec0 1948 if (ua_chan_node != NULL) {
fc34caaa 1949 /* Session exist. Contiuing. */
5b4a0ec0
DG
1950 continue;
1951 }
421cb601 1952
5b4a0ec0
DG
1953 DBG2("Channel %s not found on shadow session copy, creating it",
1954 uchan->name);
fb83fe64
JD
1955 ua_chan = alloc_ust_app_channel(uchan->name, ua_sess,
1956 &uchan->attr);
5b4a0ec0 1957 if (ua_chan == NULL) {
fc34caaa 1958 /* malloc failed FIXME: Might want to do handle ENOMEM .. */
5b4a0ec0 1959 continue;
48842b30 1960 }
5b4a0ec0 1961 shadow_copy_channel(ua_chan, uchan);
ffe60014
DG
1962 /*
1963 * The concept of metadata channel does not exist on the tracing
1964 * registry side of the session daemon so this can only be a per CPU
1965 * channel and not metadata.
1966 */
1967 ua_chan->attr.type = LTTNG_UST_CHAN_PER_CPU;
1968
bec39940 1969 lttng_ht_add_unique_str(ua_sess->channels, &ua_chan->node);
48842b30 1970 }
6addfa37 1971 return;
7972aab2
DG
1972
1973error:
6addfa37 1974 consumer_output_put(ua_sess->consumer);
48842b30
DG
1975}
1976
78f0bacd
DG
1977/*
1978 * Lookup sesison wrapper.
1979 */
84cd17c6
MD
1980static
1981void __lookup_session_by_app(struct ltt_ust_session *usess,
bec39940 1982 struct ust_app *app, struct lttng_ht_iter *iter)
84cd17c6
MD
1983{
1984 /* Get right UST app session from app */
d9bf3ca4 1985 lttng_ht_lookup(app->sessions, &usess->id, iter);
84cd17c6
MD
1986}
1987
421cb601
DG
1988/*
1989 * Return ust app session from the app session hashtable using the UST session
a991f516 1990 * id.
421cb601 1991 */
48842b30
DG
1992static struct ust_app_session *lookup_session_by_app(
1993 struct ltt_ust_session *usess, struct ust_app *app)
1994{
bec39940 1995 struct lttng_ht_iter iter;
d9bf3ca4 1996 struct lttng_ht_node_u64 *node;
48842b30 1997
84cd17c6 1998 __lookup_session_by_app(usess, app, &iter);
d9bf3ca4 1999 node = lttng_ht_iter_get_node_u64(&iter);
48842b30
DG
2000 if (node == NULL) {
2001 goto error;
2002 }
2003
2004 return caa_container_of(node, struct ust_app_session, node);
2005
2006error:
2007 return NULL;
2008}
2009
7972aab2
DG
2010/*
2011 * Setup buffer registry per PID for the given session and application. If none
2012 * is found, a new one is created, added to the global registry and
2013 * initialized. If regp is valid, it's set with the newly created object.
2014 *
2015 * Return 0 on success or else a negative value.
2016 */
2017static int setup_buffer_reg_pid(struct ust_app_session *ua_sess,
2018 struct ust_app *app, struct buffer_reg_pid **regp)
2019{
2020 int ret = 0;
2021 struct buffer_reg_pid *reg_pid;
2022
2023 assert(ua_sess);
2024 assert(app);
2025
2026 rcu_read_lock();
2027
2028 reg_pid = buffer_reg_pid_find(ua_sess->id);
2029 if (!reg_pid) {
2030 /*
2031 * This is the create channel path meaning that if there is NO
2032 * registry available, we have to create one for this session.
2033 */
d7ba1388 2034 ret = buffer_reg_pid_create(ua_sess->id, &reg_pid,
3d071855 2035 ua_sess->root_shm_path, ua_sess->shm_path);
7972aab2
DG
2036 if (ret < 0) {
2037 goto error;
2038 }
7972aab2
DG
2039 } else {
2040 goto end;
2041 }
2042
2043 /* Initialize registry. */
2044 ret = ust_registry_session_init(&reg_pid->registry->reg.ust, app,
2045 app->bits_per_long, app->uint8_t_alignment,
2046 app->uint16_t_alignment, app->uint32_t_alignment,
af6142cf
MD
2047 app->uint64_t_alignment, app->long_alignment,
2048 app->byte_order, app->version.major,
3d071855
MD
2049 app->version.minor, reg_pid->root_shm_path,
2050 reg_pid->shm_path,
d7ba1388 2051 ua_sess->euid, ua_sess->egid);
7972aab2 2052 if (ret < 0) {
286c991a
MD
2053 /*
2054 * reg_pid->registry->reg.ust is NULL upon error, so we need to
2055 * destroy the buffer registry, because it is always expected
2056 * that if the buffer registry can be found, its ust registry is
2057 * non-NULL.
2058 */
2059 buffer_reg_pid_destroy(reg_pid);
7972aab2
DG
2060 goto error;
2061 }
2062
286c991a
MD
2063 buffer_reg_pid_add(reg_pid);
2064
7972aab2
DG
2065 DBG3("UST app buffer registry per PID created successfully");
2066
2067end:
2068 if (regp) {
2069 *regp = reg_pid;
2070 }
2071error:
2072 rcu_read_unlock();
2073 return ret;
2074}
2075
2076/*
2077 * Setup buffer registry per UID for the given session and application. If none
2078 * is found, a new one is created, added to the global registry and
2079 * initialized. If regp is valid, it's set with the newly created object.
2080 *
2081 * Return 0 on success or else a negative value.
2082 */
2083static int setup_buffer_reg_uid(struct ltt_ust_session *usess,
d7ba1388 2084 struct ust_app_session *ua_sess,
7972aab2
DG
2085 struct ust_app *app, struct buffer_reg_uid **regp)
2086{
2087 int ret = 0;
2088 struct buffer_reg_uid *reg_uid;
2089
2090 assert(usess);
2091 assert(app);
2092
2093 rcu_read_lock();
2094
2095 reg_uid = buffer_reg_uid_find(usess->id, app->bits_per_long, app->uid);
2096 if (!reg_uid) {
2097 /*
2098 * This is the create channel path meaning that if there is NO
2099 * registry available, we have to create one for this session.
2100 */
2101 ret = buffer_reg_uid_create(usess->id, app->bits_per_long, app->uid,
3d071855
MD
2102 LTTNG_DOMAIN_UST, &reg_uid,
2103 ua_sess->root_shm_path, ua_sess->shm_path);
7972aab2
DG
2104 if (ret < 0) {
2105 goto error;
2106 }
7972aab2
DG
2107 } else {
2108 goto end;
2109 }
2110
2111 /* Initialize registry. */
af6142cf 2112 ret = ust_registry_session_init(&reg_uid->registry->reg.ust, NULL,
7972aab2
DG
2113 app->bits_per_long, app->uint8_t_alignment,
2114 app->uint16_t_alignment, app->uint32_t_alignment,
af6142cf
MD
2115 app->uint64_t_alignment, app->long_alignment,
2116 app->byte_order, app->version.major,
3d071855
MD
2117 app->version.minor, reg_uid->root_shm_path,
2118 reg_uid->shm_path, usess->uid, usess->gid);
7972aab2 2119 if (ret < 0) {
286c991a
MD
2120 /*
2121 * reg_uid->registry->reg.ust is NULL upon error, so we need to
2122 * destroy the buffer registry, because it is always expected
2123 * that if the buffer registry can be found, its ust registry is
2124 * non-NULL.
2125 */
2126 buffer_reg_uid_destroy(reg_uid, NULL);
7972aab2
DG
2127 goto error;
2128 }
2129 /* Add node to teardown list of the session. */
2130 cds_list_add(&reg_uid->lnode, &usess->buffer_reg_uid_list);
2131
286c991a 2132 buffer_reg_uid_add(reg_uid);
7972aab2 2133
286c991a 2134 DBG3("UST app buffer registry per UID created successfully");
7972aab2
DG
2135end:
2136 if (regp) {
2137 *regp = reg_uid;
2138 }
2139error:
2140 rcu_read_unlock();
2141 return ret;
2142}
2143
421cb601 2144/*
3d8ca23b 2145 * Create a session on the tracer side for the given app.
421cb601 2146 *
3d8ca23b
DG
2147 * On success, ua_sess_ptr is populated with the session pointer or else left
2148 * untouched. If the session was created, is_created is set to 1. On error,
2149 * it's left untouched. Note that ua_sess_ptr is mandatory but is_created can
2150 * be NULL.
2151 *
2152 * Returns 0 on success or else a negative code which is either -ENOMEM or
2153 * -ENOTCONN which is the default code if the ustctl_create_session fails.
421cb601 2154 */
3d8ca23b
DG
2155static int create_ust_app_session(struct ltt_ust_session *usess,
2156 struct ust_app *app, struct ust_app_session **ua_sess_ptr,
2157 int *is_created)
421cb601 2158{
3d8ca23b 2159 int ret, created = 0;
421cb601
DG
2160 struct ust_app_session *ua_sess;
2161
3d8ca23b
DG
2162 assert(usess);
2163 assert(app);
2164 assert(ua_sess_ptr);
2165
840cb59c 2166 health_code_update();
86acf0da 2167
421cb601
DG
2168 ua_sess = lookup_session_by_app(usess, app);
2169 if (ua_sess == NULL) {
d9bf3ca4 2170 DBG2("UST app pid: %d session id %" PRIu64 " not found, creating it",
852d0037 2171 app->pid, usess->id);
d0b96690 2172 ua_sess = alloc_ust_app_session(app);
421cb601
DG
2173 if (ua_sess == NULL) {
2174 /* Only malloc can failed so something is really wrong */
3d8ca23b
DG
2175 ret = -ENOMEM;
2176 goto error;
421cb601 2177 }
477d7741 2178 shadow_copy_session(ua_sess, usess, app);
3d8ca23b 2179 created = 1;
421cb601
DG
2180 }
2181
7972aab2
DG
2182 switch (usess->buffer_type) {
2183 case LTTNG_BUFFER_PER_PID:
2184 /* Init local registry. */
2185 ret = setup_buffer_reg_pid(ua_sess, app, NULL);
421cb601 2186 if (ret < 0) {
e64207cf 2187 delete_ust_app_session(-1, ua_sess, app);
7972aab2
DG
2188 goto error;
2189 }
2190 break;
2191 case LTTNG_BUFFER_PER_UID:
2192 /* Look for a global registry. If none exists, create one. */
d7ba1388 2193 ret = setup_buffer_reg_uid(usess, ua_sess, app, NULL);
7972aab2 2194 if (ret < 0) {
e64207cf 2195 delete_ust_app_session(-1, ua_sess, app);
7972aab2
DG
2196 goto error;
2197 }
2198 break;
2199 default:
2200 assert(0);
2201 ret = -EINVAL;
2202 goto error;
2203 }
2204
2205 health_code_update();
2206
2207 if (ua_sess->handle == -1) {
fb45065e 2208 pthread_mutex_lock(&app->sock_lock);
7972aab2 2209 ret = ustctl_create_session(app->sock);
fb45065e 2210 pthread_mutex_unlock(&app->sock_lock);
7972aab2
DG
2211 if (ret < 0) {
2212 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
2213 ERR("Creating session for app pid %d with ret %d",
ffe60014
DG
2214 app->pid, ret);
2215 } else {
2216 DBG("UST app creating session failed. Application is dead");
3757b385
DG
2217 /*
2218 * This is normal behavior, an application can die during the
2219 * creation process. Don't report an error so the execution can
2220 * continue normally. This will get flagged ENOTCONN and the
2221 * caller will handle it.
2222 */
2223 ret = 0;
ffe60014 2224 }
d0b96690 2225 delete_ust_app_session(-1, ua_sess, app);
3d8ca23b
DG
2226 if (ret != -ENOMEM) {
2227 /*
2228 * Tracer is probably gone or got an internal error so let's
2229 * behave like it will soon unregister or not usable.
2230 */
2231 ret = -ENOTCONN;
2232 }
2233 goto error;
421cb601
DG
2234 }
2235
7972aab2
DG
2236 ua_sess->handle = ret;
2237
2238 /* Add ust app session to app's HT */
d9bf3ca4
MD
2239 lttng_ht_node_init_u64(&ua_sess->node,
2240 ua_sess->tracing_id);
2241 lttng_ht_add_unique_u64(app->sessions, &ua_sess->node);
10b56aef
MD
2242 lttng_ht_node_init_ulong(&ua_sess->ust_objd_node, ua_sess->handle);
2243 lttng_ht_add_unique_ulong(app->ust_sessions_objd,
2244 &ua_sess->ust_objd_node);
7972aab2
DG
2245
2246 DBG2("UST app session created successfully with handle %d", ret);
2247 }
2248
2249 *ua_sess_ptr = ua_sess;
2250 if (is_created) {
2251 *is_created = created;
2252 }
2253
2254 /* Everything went well. */
2255 ret = 0;
2256
2257error:
2258 health_code_update();
2259 return ret;
2260}
2261
6a6b2068
JG
2262/*
2263 * Match function for a hash table lookup of ust_app_ctx.
2264 *
2265 * It matches an ust app context based on the context type and, in the case
2266 * of perf counters, their name.
2267 */
2268static int ht_match_ust_app_ctx(struct cds_lfht_node *node, const void *_key)
2269{
2270 struct ust_app_ctx *ctx;
bdf64013 2271 const struct lttng_ust_context_attr *key;
6a6b2068
JG
2272
2273 assert(node);
2274 assert(_key);
2275
2276 ctx = caa_container_of(node, struct ust_app_ctx, node.node);
2277 key = _key;
2278
2279 /* Context type */
2280 if (ctx->ctx.ctx != key->ctx) {
2281 goto no_match;
2282 }
2283
bdf64013
JG
2284 switch(key->ctx) {
2285 case LTTNG_UST_CONTEXT_PERF_THREAD_COUNTER:
6a6b2068 2286 if (strncmp(key->u.perf_counter.name,
bdf64013
JG
2287 ctx->ctx.u.perf_counter.name,
2288 sizeof(key->u.perf_counter.name))) {
2289 goto no_match;
2290 }
2291 break;
2292 case LTTNG_UST_CONTEXT_APP_CONTEXT:
2293 if (strcmp(key->u.app_ctx.provider_name,
2294 ctx->ctx.u.app_ctx.provider_name) ||
2295 strcmp(key->u.app_ctx.ctx_name,
2296 ctx->ctx.u.app_ctx.ctx_name)) {
6a6b2068
JG
2297 goto no_match;
2298 }
bdf64013
JG
2299 break;
2300 default:
2301 break;
6a6b2068
JG
2302 }
2303
2304 /* Match. */
2305 return 1;
2306
2307no_match:
2308 return 0;
2309}
2310
2311/*
2312 * Lookup for an ust app context from an lttng_ust_context.
2313 *
be184a0f 2314 * Must be called while holding RCU read side lock.
6a6b2068
JG
2315 * Return an ust_app_ctx object or NULL on error.
2316 */
2317static
2318struct ust_app_ctx *find_ust_app_context(struct lttng_ht *ht,
bdf64013 2319 struct lttng_ust_context_attr *uctx)
6a6b2068
JG
2320{
2321 struct lttng_ht_iter iter;
2322 struct lttng_ht_node_ulong *node;
2323 struct ust_app_ctx *app_ctx = NULL;
2324
2325 assert(uctx);
2326 assert(ht);
2327
2328 /* Lookup using the lttng_ust_context_type and a custom match fct. */
2329 cds_lfht_lookup(ht->ht, ht->hash_fct((void *) uctx->ctx, lttng_ht_seed),
2330 ht_match_ust_app_ctx, uctx, &iter.iter);
2331 node = lttng_ht_iter_get_node_ulong(&iter);
2332 if (!node) {
2333 goto end;
2334 }
2335
2336 app_ctx = caa_container_of(node, struct ust_app_ctx, node);
2337
2338end:
2339 return app_ctx;
2340}
2341
7972aab2
DG
2342/*
2343 * Create a context for the channel on the tracer.
2344 *
2345 * Called with UST app session lock held and a RCU read side lock.
2346 */
2347static
2348int create_ust_app_channel_context(struct ust_app_session *ua_sess,
bdf64013
JG
2349 struct ust_app_channel *ua_chan,
2350 struct lttng_ust_context_attr *uctx,
7972aab2
DG
2351 struct ust_app *app)
2352{
2353 int ret = 0;
7972aab2
DG
2354 struct ust_app_ctx *ua_ctx;
2355
2356 DBG2("UST app adding context to channel %s", ua_chan->name);
2357
6a6b2068
JG
2358 ua_ctx = find_ust_app_context(ua_chan->ctx, uctx);
2359 if (ua_ctx) {
7972aab2
DG
2360 ret = -EEXIST;
2361 goto error;
2362 }
2363
2364 ua_ctx = alloc_ust_app_ctx(uctx);
2365 if (ua_ctx == NULL) {
2366 /* malloc failed */
2367 ret = -1;
2368 goto error;
2369 }
2370
2371 lttng_ht_node_init_ulong(&ua_ctx->node, (unsigned long) ua_ctx->ctx.ctx);
aa3514e9 2372 lttng_ht_add_ulong(ua_chan->ctx, &ua_ctx->node);
31746f93 2373 cds_list_add_tail(&ua_ctx->list, &ua_chan->ctx_list);
7972aab2
DG
2374
2375 ret = create_ust_channel_context(ua_chan, ua_ctx, app);
2376 if (ret < 0) {
2377 goto error;
2378 }
2379
2380error:
2381 return ret;
2382}
2383
2384/*
2385 * Enable on the tracer side a ust app event for the session and channel.
2386 *
2387 * Called with UST app session lock held.
2388 */
2389static
2390int enable_ust_app_event(struct ust_app_session *ua_sess,
2391 struct ust_app_event *ua_event, struct ust_app *app)
2392{
2393 int ret;
2394
2395 ret = enable_ust_event(app, ua_sess, ua_event);
2396 if (ret < 0) {
2397 goto error;
2398 }
2399
2400 ua_event->enabled = 1;
2401
2402error:
2403 return ret;
2404}
2405
2406/*
2407 * Disable on the tracer side a ust app event for the session and channel.
2408 */
2409static int disable_ust_app_event(struct ust_app_session *ua_sess,
2410 struct ust_app_event *ua_event, struct ust_app *app)
2411{
2412 int ret;
2413
2414 ret = disable_ust_event(app, ua_sess, ua_event);
2415 if (ret < 0) {
2416 goto error;
2417 }
2418
2419 ua_event->enabled = 0;
2420
2421error:
2422 return ret;
2423}
2424
2425/*
2426 * Lookup ust app channel for session and disable it on the tracer side.
2427 */
2428static
2429int disable_ust_app_channel(struct ust_app_session *ua_sess,
2430 struct ust_app_channel *ua_chan, struct ust_app *app)
2431{
2432 int ret;
2433
2434 ret = disable_ust_channel(app, ua_sess, ua_chan);
2435 if (ret < 0) {
2436 goto error;
2437 }
2438
2439 ua_chan->enabled = 0;
2440
2441error:
2442 return ret;
2443}
2444
2445/*
2446 * Lookup ust app channel for session and enable it on the tracer side. This
2447 * MUST be called with a RCU read side lock acquired.
2448 */
2449static int enable_ust_app_channel(struct ust_app_session *ua_sess,
2450 struct ltt_ust_channel *uchan, struct ust_app *app)
2451{
2452 int ret = 0;
2453 struct lttng_ht_iter iter;
2454 struct lttng_ht_node_str *ua_chan_node;
2455 struct ust_app_channel *ua_chan;
2456
2457 lttng_ht_lookup(ua_sess->channels, (void *)uchan->name, &iter);
2458 ua_chan_node = lttng_ht_iter_get_node_str(&iter);
2459 if (ua_chan_node == NULL) {
d9bf3ca4 2460 DBG2("Unable to find channel %s in ust session id %" PRIu64,
7972aab2
DG
2461 uchan->name, ua_sess->tracing_id);
2462 goto error;
2463 }
2464
2465 ua_chan = caa_container_of(ua_chan_node, struct ust_app_channel, node);
2466
2467 ret = enable_ust_channel(app, ua_sess, ua_chan);
2468 if (ret < 0) {
2469 goto error;
2470 }
2471
2472error:
2473 return ret;
2474}
2475
2476/*
2477 * Ask the consumer to create a channel and get it if successful.
2478 *
2479 * Return 0 on success or else a negative value.
2480 */
2481static int do_consumer_create_channel(struct ltt_ust_session *usess,
2482 struct ust_app_session *ua_sess, struct ust_app_channel *ua_chan,
2483 int bitness, struct ust_registry_session *registry)
2484{
2485 int ret;
2486 unsigned int nb_fd = 0;
2487 struct consumer_socket *socket;
2488
2489 assert(usess);
2490 assert(ua_sess);
2491 assert(ua_chan);
2492 assert(registry);
2493
2494 rcu_read_lock();
2495 health_code_update();
2496
2497 /* Get the right consumer socket for the application. */
2498 socket = consumer_find_socket_by_bitness(bitness, usess->consumer);
2499 if (!socket) {
2500 ret = -EINVAL;
2501 goto error;
2502 }
2503
2504 health_code_update();
2505
2506 /* Need one fd for the channel. */
2507 ret = lttng_fd_get(LTTNG_FD_APPS, 1);
2508 if (ret < 0) {
2509 ERR("Exhausted number of available FD upon create channel");
2510 goto error;
2511 }
2512
2513 /*
2514 * Ask consumer to create channel. The consumer will return the number of
2515 * stream we have to expect.
2516 */
2517 ret = ust_consumer_ask_channel(ua_sess, ua_chan, usess->consumer, socket,
2518 registry);
2519 if (ret < 0) {
2520 goto error_ask;
2521 }
2522
2523 /*
2524 * Compute the number of fd needed before receiving them. It must be 2 per
2525 * stream (2 being the default value here).
2526 */
2527 nb_fd = DEFAULT_UST_STREAM_FD_NUM * ua_chan->expected_stream_count;
2528
2529 /* Reserve the amount of file descriptor we need. */
2530 ret = lttng_fd_get(LTTNG_FD_APPS, nb_fd);
2531 if (ret < 0) {
2532 ERR("Exhausted number of available FD upon create channel");
2533 goto error_fd_get_stream;
2534 }
2535
2536 health_code_update();
2537
2538 /*
2539 * Now get the channel from the consumer. This call wil populate the stream
2540 * list of that channel and set the ust objects.
2541 */
d9078d0c
DG
2542 if (usess->consumer->enabled) {
2543 ret = ust_consumer_get_channel(socket, ua_chan);
2544 if (ret < 0) {
2545 goto error_destroy;
2546 }
7972aab2
DG
2547 }
2548
2549 rcu_read_unlock();
2550 return 0;
2551
2552error_destroy:
2553 lttng_fd_put(LTTNG_FD_APPS, nb_fd);
2554error_fd_get_stream:
2555 /*
2556 * Initiate a destroy channel on the consumer since we had an error
2557 * handling it on our side. The return value is of no importance since we
2558 * already have a ret value set by the previous error that we need to
2559 * return.
2560 */
2561 (void) ust_consumer_destroy_channel(socket, ua_chan);
2562error_ask:
2563 lttng_fd_put(LTTNG_FD_APPS, 1);
2564error:
2565 health_code_update();
2566 rcu_read_unlock();
2567 return ret;
2568}
2569
2570/*
2571 * Duplicate the ust data object of the ust app stream and save it in the
2572 * buffer registry stream.
2573 *
2574 * Return 0 on success or else a negative value.
2575 */
2576static int duplicate_stream_object(struct buffer_reg_stream *reg_stream,
2577 struct ust_app_stream *stream)
2578{
2579 int ret;
2580
2581 assert(reg_stream);
2582 assert(stream);
2583
2584 /* Reserve the amount of file descriptor we need. */
2585 ret = lttng_fd_get(LTTNG_FD_APPS, 2);
2586 if (ret < 0) {
2587 ERR("Exhausted number of available FD upon duplicate stream");
2588 goto error;
2589 }
2590
2591 /* Duplicate object for stream once the original is in the registry. */
2592 ret = ustctl_duplicate_ust_object_data(&stream->obj,
2593 reg_stream->obj.ust);
2594 if (ret < 0) {
2595 ERR("Duplicate stream obj from %p to %p failed with ret %d",
2596 reg_stream->obj.ust, stream->obj, ret);
2597 lttng_fd_put(LTTNG_FD_APPS, 2);
2598 goto error;
2599 }
2600 stream->handle = stream->obj->handle;
2601
2602error:
2603 return ret;
2604}
2605
2606/*
2607 * Duplicate the ust data object of the ust app. channel and save it in the
2608 * buffer registry channel.
2609 *
2610 * Return 0 on success or else a negative value.
2611 */
2612static int duplicate_channel_object(struct buffer_reg_channel *reg_chan,
2613 struct ust_app_channel *ua_chan)
2614{
2615 int ret;
2616
2617 assert(reg_chan);
2618 assert(ua_chan);
2619
2620 /* Need two fds for the channel. */
2621 ret = lttng_fd_get(LTTNG_FD_APPS, 1);
2622 if (ret < 0) {
2623 ERR("Exhausted number of available FD upon duplicate channel");
2624 goto error_fd_get;
2625 }
2626
2627 /* Duplicate object for stream once the original is in the registry. */
2628 ret = ustctl_duplicate_ust_object_data(&ua_chan->obj, reg_chan->obj.ust);
2629 if (ret < 0) {
2630 ERR("Duplicate channel obj from %p to %p failed with ret: %d",
2631 reg_chan->obj.ust, ua_chan->obj, ret);
2632 goto error;
2633 }
2634 ua_chan->handle = ua_chan->obj->handle;
2635
2636 return 0;
2637
2638error:
2639 lttng_fd_put(LTTNG_FD_APPS, 1);
2640error_fd_get:
2641 return ret;
2642}
2643
2644/*
2645 * For a given channel buffer registry, setup all streams of the given ust
2646 * application channel.
2647 *
2648 * Return 0 on success or else a negative value.
2649 */
2650static int setup_buffer_reg_streams(struct buffer_reg_channel *reg_chan,
fb45065e
MD
2651 struct ust_app_channel *ua_chan,
2652 struct ust_app *app)
7972aab2
DG
2653{
2654 int ret = 0;
2655 struct ust_app_stream *stream, *stmp;
2656
2657 assert(reg_chan);
2658 assert(ua_chan);
2659
2660 DBG2("UST app setup buffer registry stream");
2661
2662 /* Send all streams to application. */
2663 cds_list_for_each_entry_safe(stream, stmp, &ua_chan->streams.head, list) {
2664 struct buffer_reg_stream *reg_stream;
2665
2666 ret = buffer_reg_stream_create(&reg_stream);
2667 if (ret < 0) {
2668 goto error;
2669 }
2670
2671 /*
2672 * Keep original pointer and nullify it in the stream so the delete
2673 * stream call does not release the object.
2674 */
2675 reg_stream->obj.ust = stream->obj;
2676 stream->obj = NULL;
2677 buffer_reg_stream_add(reg_stream, reg_chan);
421cb601 2678
7972aab2
DG
2679 /* We don't need the streams anymore. */
2680 cds_list_del(&stream->list);
fb45065e 2681 delete_ust_app_stream(-1, stream, app);
7972aab2 2682 }
421cb601 2683
7972aab2
DG
2684error:
2685 return ret;
2686}
2687
2688/*
2689 * Create a buffer registry channel for the given session registry and
2690 * application channel object. If regp pointer is valid, it's set with the
2691 * created object. Important, the created object is NOT added to the session
2692 * registry hash table.
2693 *
2694 * Return 0 on success else a negative value.
2695 */
2696static int create_buffer_reg_channel(struct buffer_reg_session *reg_sess,
2697 struct ust_app_channel *ua_chan, struct buffer_reg_channel **regp)
2698{
2699 int ret;
2700 struct buffer_reg_channel *reg_chan = NULL;
2701
2702 assert(reg_sess);
2703 assert(ua_chan);
2704
2705 DBG2("UST app creating buffer registry channel for %s", ua_chan->name);
2706
2707 /* Create buffer registry channel. */
2708 ret = buffer_reg_channel_create(ua_chan->tracing_channel_id, &reg_chan);
2709 if (ret < 0) {
2710 goto error_create;
421cb601 2711 }
7972aab2
DG
2712 assert(reg_chan);
2713 reg_chan->consumer_key = ua_chan->key;
8c924c7b 2714 reg_chan->subbuf_size = ua_chan->attr.subbuf_size;
d07ceecd 2715 reg_chan->num_subbuf = ua_chan->attr.num_subbuf;
421cb601 2716
7972aab2
DG
2717 /* Create and add a channel registry to session. */
2718 ret = ust_registry_channel_add(reg_sess->reg.ust,
2719 ua_chan->tracing_channel_id);
2720 if (ret < 0) {
2721 goto error;
d88aee68 2722 }
7972aab2 2723 buffer_reg_channel_add(reg_sess, reg_chan);
d88aee68 2724
7972aab2
DG
2725 if (regp) {
2726 *regp = reg_chan;
3d8ca23b 2727 }
d88aee68 2728
7972aab2 2729 return 0;
3d8ca23b
DG
2730
2731error:
7972aab2
DG
2732 /* Safe because the registry channel object was not added to any HT. */
2733 buffer_reg_channel_destroy(reg_chan, LTTNG_DOMAIN_UST);
2734error_create:
3d8ca23b 2735 return ret;
421cb601
DG
2736}
2737
55cc08a6 2738/*
7972aab2
DG
2739 * Setup buffer registry channel for the given session registry and application
2740 * channel object. If regp pointer is valid, it's set with the created object.
d0b96690 2741 *
7972aab2 2742 * Return 0 on success else a negative value.
55cc08a6 2743 */
7972aab2 2744static int setup_buffer_reg_channel(struct buffer_reg_session *reg_sess,
fb45065e
MD
2745 struct ust_app_channel *ua_chan, struct buffer_reg_channel *reg_chan,
2746 struct ust_app *app)
55cc08a6 2747{
7972aab2 2748 int ret;
55cc08a6 2749
7972aab2
DG
2750 assert(reg_sess);
2751 assert(reg_chan);
2752 assert(ua_chan);
2753 assert(ua_chan->obj);
55cc08a6 2754
7972aab2 2755 DBG2("UST app setup buffer registry channel for %s", ua_chan->name);
55cc08a6 2756
7972aab2 2757 /* Setup all streams for the registry. */
fb45065e 2758 ret = setup_buffer_reg_streams(reg_chan, ua_chan, app);
7972aab2 2759 if (ret < 0) {
55cc08a6
DG
2760 goto error;
2761 }
2762
7972aab2
DG
2763 reg_chan->obj.ust = ua_chan->obj;
2764 ua_chan->obj = NULL;
55cc08a6 2765
7972aab2 2766 return 0;
55cc08a6
DG
2767
2768error:
7972aab2
DG
2769 buffer_reg_channel_remove(reg_sess, reg_chan);
2770 buffer_reg_channel_destroy(reg_chan, LTTNG_DOMAIN_UST);
55cc08a6
DG
2771 return ret;
2772}
2773
edb67388 2774/*
7972aab2 2775 * Send buffer registry channel to the application.
d0b96690 2776 *
7972aab2 2777 * Return 0 on success else a negative value.
edb67388 2778 */
7972aab2
DG
2779static int send_channel_uid_to_ust(struct buffer_reg_channel *reg_chan,
2780 struct ust_app *app, struct ust_app_session *ua_sess,
2781 struct ust_app_channel *ua_chan)
edb67388
DG
2782{
2783 int ret;
7972aab2 2784 struct buffer_reg_stream *reg_stream;
edb67388 2785
7972aab2
DG
2786 assert(reg_chan);
2787 assert(app);
2788 assert(ua_sess);
2789 assert(ua_chan);
2790
2791 DBG("UST app sending buffer registry channel to ust sock %d", app->sock);
2792
2793 ret = duplicate_channel_object(reg_chan, ua_chan);
edb67388
DG
2794 if (ret < 0) {
2795 goto error;
2796 }
2797
7972aab2
DG
2798 /* Send channel to the application. */
2799 ret = ust_consumer_send_channel_to_ust(app, ua_sess, ua_chan);
a7169585
MD
2800 if (ret == -EPIPE || ret == -LTTNG_UST_ERR_EXITING) {
2801 ret = -ENOTCONN; /* Caused by app exiting. */
2802 goto error;
2803 } else if (ret < 0) {
7972aab2
DG
2804 goto error;
2805 }
2806
2807 health_code_update();
2808
2809 /* Send all streams to application. */
2810 pthread_mutex_lock(&reg_chan->stream_list_lock);
2811 cds_list_for_each_entry(reg_stream, &reg_chan->streams, lnode) {
2812 struct ust_app_stream stream;
2813
2814 ret = duplicate_stream_object(reg_stream, &stream);
2815 if (ret < 0) {
2816 goto error_stream_unlock;
2817 }
2818
2819 ret = ust_consumer_send_stream_to_ust(app, ua_chan, &stream);
2820 if (ret < 0) {
fb45065e 2821 (void) release_ust_app_stream(-1, &stream, app);
a7169585
MD
2822 if (ret == -EPIPE || ret == -LTTNG_UST_ERR_EXITING) {
2823 ret = -ENOTCONN; /* Caused by app exiting. */
2824 goto error_stream_unlock;
2825 } else if (ret < 0) {
2826 goto error_stream_unlock;
2827 }
7972aab2
DG
2828 goto error_stream_unlock;
2829 }
edb67388 2830
7972aab2
DG
2831 /*
2832 * The return value is not important here. This function will output an
2833 * error if needed.
2834 */
fb45065e 2835 (void) release_ust_app_stream(-1, &stream, app);
7972aab2
DG
2836 }
2837 ua_chan->is_sent = 1;
2838
2839error_stream_unlock:
2840 pthread_mutex_unlock(&reg_chan->stream_list_lock);
edb67388
DG
2841error:
2842 return ret;
2843}
2844
9730260e 2845/*
7972aab2
DG
2846 * Create and send to the application the created buffers with per UID buffers.
2847 *
2848 * Return 0 on success else a negative value.
9730260e 2849 */
7972aab2
DG
2850static int create_channel_per_uid(struct ust_app *app,
2851 struct ltt_ust_session *usess, struct ust_app_session *ua_sess,
2852 struct ust_app_channel *ua_chan)
9730260e
DG
2853{
2854 int ret;
7972aab2
DG
2855 struct buffer_reg_uid *reg_uid;
2856 struct buffer_reg_channel *reg_chan;
9730260e 2857
7972aab2
DG
2858 assert(app);
2859 assert(usess);
2860 assert(ua_sess);
2861 assert(ua_chan);
2862
2863 DBG("UST app creating channel %s with per UID buffers", ua_chan->name);
2864
2865 reg_uid = buffer_reg_uid_find(usess->id, app->bits_per_long, app->uid);
2866 /*
2867 * The session creation handles the creation of this global registry
2868 * object. If none can be find, there is a code flow problem or a
2869 * teardown race.
2870 */
2871 assert(reg_uid);
2872
2873 reg_chan = buffer_reg_channel_find(ua_chan->tracing_channel_id,
2874 reg_uid);
2875 if (!reg_chan) {
2876 /* Create the buffer registry channel object. */
2877 ret = create_buffer_reg_channel(reg_uid->registry, ua_chan, &reg_chan);
2878 if (ret < 0) {
f14256d6
MD
2879 ERR("Error creating the UST channel \"%s\" registry instance",
2880 ua_chan->name);
7972aab2
DG
2881 goto error;
2882 }
2883 assert(reg_chan);
2884
2885 /*
2886 * Create the buffers on the consumer side. This call populates the
2887 * ust app channel object with all streams and data object.
2888 */
2889 ret = do_consumer_create_channel(usess, ua_sess, ua_chan,
2890 app->bits_per_long, reg_uid->registry->reg.ust);
2891 if (ret < 0) {
f14256d6
MD
2892 ERR("Error creating UST channel \"%s\" on the consumer daemon",
2893 ua_chan->name);
2894
07d2ae95
DG
2895 /*
2896 * Let's remove the previously created buffer registry channel so
2897 * it's not visible anymore in the session registry.
2898 */
2899 ust_registry_channel_del_free(reg_uid->registry->reg.ust,
2900 ua_chan->tracing_channel_id);
2901 buffer_reg_channel_remove(reg_uid->registry, reg_chan);
2902 buffer_reg_channel_destroy(reg_chan, LTTNG_DOMAIN_UST);
7972aab2
DG
2903 goto error;
2904 }
2905
2906 /*
2907 * Setup the streams and add it to the session registry.
2908 */
fb45065e
MD
2909 ret = setup_buffer_reg_channel(reg_uid->registry,
2910 ua_chan, reg_chan, app);
7972aab2 2911 if (ret < 0) {
f14256d6
MD
2912 ERR("Error setting up UST channel \"%s\"",
2913 ua_chan->name);
7972aab2
DG
2914 goto error;
2915 }
2916
2917 }
2918
2919 /* Send buffers to the application. */
2920 ret = send_channel_uid_to_ust(reg_chan, app, ua_sess, ua_chan);
9730260e 2921 if (ret < 0) {
a7169585
MD
2922 if (ret != -ENOTCONN) {
2923 ERR("Error sending channel to application");
2924 }
9730260e
DG
2925 goto error;
2926 }
2927
9730260e
DG
2928error:
2929 return ret;
2930}
2931
78f0bacd 2932/*
7972aab2
DG
2933 * Create and send to the application the created buffers with per PID buffers.
2934 *
2935 * Return 0 on success else a negative value.
78f0bacd 2936 */
7972aab2
DG
2937static int create_channel_per_pid(struct ust_app *app,
2938 struct ltt_ust_session *usess, struct ust_app_session *ua_sess,
2939 struct ust_app_channel *ua_chan)
78f0bacd 2940{
8535a6d9 2941 int ret;
7972aab2 2942 struct ust_registry_session *registry;
78f0bacd 2943
7972aab2
DG
2944 assert(app);
2945 assert(usess);
2946 assert(ua_sess);
2947 assert(ua_chan);
2948
2949 DBG("UST app creating channel %s with per PID buffers", ua_chan->name);
2950
2951 rcu_read_lock();
2952
2953 registry = get_session_registry(ua_sess);
2954 assert(registry);
2955
2956 /* Create and add a new channel registry to session. */
2957 ret = ust_registry_channel_add(registry, ua_chan->key);
78f0bacd 2958 if (ret < 0) {
f14256d6
MD
2959 ERR("Error creating the UST channel \"%s\" registry instance",
2960 ua_chan->name);
78f0bacd
DG
2961 goto error;
2962 }
2963
7972aab2
DG
2964 /* Create and get channel on the consumer side. */
2965 ret = do_consumer_create_channel(usess, ua_sess, ua_chan,
2966 app->bits_per_long, registry);
2967 if (ret < 0) {
f14256d6
MD
2968 ERR("Error creating UST channel \"%s\" on the consumer daemon",
2969 ua_chan->name);
7972aab2
DG
2970 goto error;
2971 }
2972
2973 ret = send_channel_pid_to_ust(app, ua_sess, ua_chan);
2974 if (ret < 0) {
a7169585
MD
2975 if (ret != -ENOTCONN) {
2976 ERR("Error sending channel to application");
2977 }
7972aab2
DG
2978 goto error;
2979 }
8535a6d9 2980
78f0bacd 2981error:
7972aab2 2982 rcu_read_unlock();
78f0bacd
DG
2983 return ret;
2984}
2985
2986/*
7972aab2
DG
2987 * From an already allocated ust app channel, create the channel buffers if
2988 * need and send it to the application. This MUST be called with a RCU read
2989 * side lock acquired.
2990 *
a7169585
MD
2991 * Return 0 on success or else a negative value. Returns -ENOTCONN if
2992 * the application exited concurrently.
78f0bacd 2993 */
7972aab2
DG
2994static int do_create_channel(struct ust_app *app,
2995 struct ltt_ust_session *usess, struct ust_app_session *ua_sess,
2996 struct ust_app_channel *ua_chan)
78f0bacd 2997{
7972aab2 2998 int ret;
78f0bacd 2999
7972aab2
DG
3000 assert(app);
3001 assert(usess);
3002 assert(ua_sess);
3003 assert(ua_chan);
3004
3005 /* Handle buffer type before sending the channel to the application. */
3006 switch (usess->buffer_type) {
3007 case LTTNG_BUFFER_PER_UID:
3008 {
3009 ret = create_channel_per_uid(app, usess, ua_sess, ua_chan);
3010 if (ret < 0) {
3011 goto error;
3012 }
3013 break;
3014 }
3015 case LTTNG_BUFFER_PER_PID:
3016 {
3017 ret = create_channel_per_pid(app, usess, ua_sess, ua_chan);
3018 if (ret < 0) {
3019 goto error;
3020 }
3021 break;
3022 }
3023 default:
3024 assert(0);
3025 ret = -EINVAL;
78f0bacd
DG
3026 goto error;
3027 }
3028
7972aab2
DG
3029 /* Initialize ust objd object using the received handle and add it. */
3030 lttng_ht_node_init_ulong(&ua_chan->ust_objd_node, ua_chan->handle);
3031 lttng_ht_add_unique_ulong(app->ust_objd, &ua_chan->ust_objd_node);
78f0bacd 3032
7972aab2
DG
3033 /* If channel is not enabled, disable it on the tracer */
3034 if (!ua_chan->enabled) {
3035 ret = disable_ust_channel(app, ua_sess, ua_chan);
3036 if (ret < 0) {
3037 goto error;
3038 }
78f0bacd
DG
3039 }
3040
3041error:
3042 return ret;
3043}
3044
284d8f55 3045/*
4d710ac2
DG
3046 * Create UST app channel and create it on the tracer. Set ua_chanp of the
3047 * newly created channel if not NULL.
d0b96690 3048 *
36b588ed 3049 * Called with UST app session lock and RCU read-side lock held.
7972aab2 3050 *
a7169585
MD
3051 * Return 0 on success or else a negative value. Returns -ENOTCONN if
3052 * the application exited concurrently.
284d8f55 3053 */
4d710ac2
DG
3054static int create_ust_app_channel(struct ust_app_session *ua_sess,
3055 struct ltt_ust_channel *uchan, struct ust_app *app,
7972aab2 3056 enum lttng_ust_chan_type type, struct ltt_ust_session *usess,
4d710ac2 3057 struct ust_app_channel **ua_chanp)
5b4a0ec0
DG
3058{
3059 int ret = 0;
bec39940
DG
3060 struct lttng_ht_iter iter;
3061 struct lttng_ht_node_str *ua_chan_node;
5b4a0ec0
DG
3062 struct ust_app_channel *ua_chan;
3063
3064 /* Lookup channel in the ust app session */
bec39940
DG
3065 lttng_ht_lookup(ua_sess->channels, (void *)uchan->name, &iter);
3066 ua_chan_node = lttng_ht_iter_get_node_str(&iter);
fc34caaa 3067 if (ua_chan_node != NULL) {
5b4a0ec0 3068 ua_chan = caa_container_of(ua_chan_node, struct ust_app_channel, node);
fc34caaa 3069 goto end;
5b4a0ec0
DG
3070 }
3071
d0b96690 3072 ua_chan = alloc_ust_app_channel(uchan->name, ua_sess, &uchan->attr);
fc34caaa
DG
3073 if (ua_chan == NULL) {
3074 /* Only malloc can fail here */
4d710ac2 3075 ret = -ENOMEM;
094d1690 3076 goto error_alloc;
fc34caaa
DG
3077 }
3078 shadow_copy_channel(ua_chan, uchan);
3079
ffe60014
DG
3080 /* Set channel type. */
3081 ua_chan->attr.type = type;
3082
7972aab2 3083 ret = do_create_channel(app, usess, ua_sess, ua_chan);
5b4a0ec0
DG
3084 if (ret < 0) {
3085 goto error;
3086 }
3087
fc34caaa 3088 DBG2("UST app create channel %s for PID %d completed", ua_chan->name,
852d0037 3089 app->pid);
fc34caaa 3090
d0b96690
DG
3091 /* Only add the channel if successful on the tracer side. */
3092 lttng_ht_add_unique_str(ua_sess->channels, &ua_chan->node);
3093
fc34caaa 3094end:
4d710ac2
DG
3095 if (ua_chanp) {
3096 *ua_chanp = ua_chan;
3097 }
3098
3099 /* Everything went well. */
3100 return 0;
5b4a0ec0
DG
3101
3102error:
d0b96690 3103 delete_ust_app_channel(ua_chan->is_sent ? app->sock : -1, ua_chan, app);
094d1690 3104error_alloc:
4d710ac2 3105 return ret;
5b4a0ec0
DG
3106}
3107
3108/*
3109 * Create UST app event and create it on the tracer side.
d0b96690
DG
3110 *
3111 * Called with ust app session mutex held.
5b4a0ec0 3112 */
edb67388
DG
3113static
3114int create_ust_app_event(struct ust_app_session *ua_sess,
3115 struct ust_app_channel *ua_chan, struct ltt_ust_event *uevent,
3116 struct ust_app *app)
284d8f55 3117{
edb67388 3118 int ret = 0;
5b4a0ec0 3119 struct ust_app_event *ua_event;
284d8f55 3120
5b4a0ec0 3121 /* Get event node */
18eace3b 3122 ua_event = find_ust_app_event(ua_chan->events, uevent->attr.name,
39c5a3a7 3123 uevent->filter, uevent->attr.loglevel, uevent->exclusion);
18eace3b 3124 if (ua_event != NULL) {
fc34caaa 3125 ret = -EEXIST;
edb67388
DG
3126 goto end;
3127 }
5b4a0ec0 3128
edb67388
DG
3129 /* Does not exist so create one */
3130 ua_event = alloc_ust_app_event(uevent->attr.name, &uevent->attr);
3131 if (ua_event == NULL) {
3132 /* Only malloc can failed so something is really wrong */
3133 ret = -ENOMEM;
fc34caaa 3134 goto end;
5b4a0ec0 3135 }
edb67388 3136 shadow_copy_event(ua_event, uevent);
5b4a0ec0 3137
edb67388 3138 /* Create it on the tracer side */
5b4a0ec0 3139 ret = create_ust_event(app, ua_sess, ua_chan, ua_event);
284d8f55 3140 if (ret < 0) {
fc34caaa 3141 /* Not found previously means that it does not exist on the tracer */
76f66f63 3142 assert(ret != -LTTNG_UST_ERR_EXIST);
284d8f55
DG
3143 goto error;
3144 }
3145
d0b96690 3146 add_unique_ust_app_event(ua_chan, ua_event);
284d8f55 3147
fc34caaa 3148 DBG2("UST app create event %s for PID %d completed", ua_event->name,
852d0037 3149 app->pid);
7f79d3a1 3150
edb67388 3151end:
fc34caaa
DG
3152 return ret;
3153
5b4a0ec0 3154error:
fc34caaa 3155 /* Valid. Calling here is already in a read side lock */
fb45065e 3156 delete_ust_app_event(-1, ua_event, app);
edb67388 3157 return ret;
5b4a0ec0
DG
3158}
3159
3160/*
3161 * Create UST metadata and open it on the tracer side.
d0b96690 3162 *
7972aab2 3163 * Called with UST app session lock held and RCU read side lock.
5b4a0ec0
DG
3164 */
3165static int create_ust_app_metadata(struct ust_app_session *ua_sess,
ad7a9107 3166 struct ust_app *app, struct consumer_output *consumer)
5b4a0ec0
DG
3167{
3168 int ret = 0;
ffe60014 3169 struct ust_app_channel *metadata;
d88aee68 3170 struct consumer_socket *socket;
7972aab2 3171 struct ust_registry_session *registry;
5b4a0ec0 3172
ffe60014
DG
3173 assert(ua_sess);
3174 assert(app);
d88aee68 3175 assert(consumer);
5b4a0ec0 3176
7972aab2
DG
3177 registry = get_session_registry(ua_sess);
3178 assert(registry);
3179
ce34fcd0
MD
3180 pthread_mutex_lock(&registry->lock);
3181
1b532a60
DG
3182 /* Metadata already exists for this registry or it was closed previously */
3183 if (registry->metadata_key || registry->metadata_closed) {
7972aab2
DG
3184 ret = 0;
3185 goto error;
5b4a0ec0
DG
3186 }
3187
ffe60014 3188 /* Allocate UST metadata */
d0b96690 3189 metadata = alloc_ust_app_channel(DEFAULT_METADATA_NAME, ua_sess, NULL);
ffe60014
DG
3190 if (!metadata) {
3191 /* malloc() failed */
3192 ret = -ENOMEM;
3193 goto error;
3194 }
5b4a0ec0 3195
ad7a9107 3196 memcpy(&metadata->attr, &ua_sess->metadata_attr, sizeof(metadata->attr));
5b4a0ec0 3197
7972aab2
DG
3198 /* Need one fd for the channel. */
3199 ret = lttng_fd_get(LTTNG_FD_APPS, 1);
3200 if (ret < 0) {
3201 ERR("Exhausted number of available FD upon create metadata");
3202 goto error;
3203 }
3204
4dc3dfc5
DG
3205 /* Get the right consumer socket for the application. */
3206 socket = consumer_find_socket_by_bitness(app->bits_per_long, consumer);
3207 if (!socket) {
3208 ret = -EINVAL;
3209 goto error_consumer;
3210 }
3211
331744e3
JD
3212 /*
3213 * Keep metadata key so we can identify it on the consumer side. Assign it
3214 * to the registry *before* we ask the consumer so we avoid the race of the
3215 * consumer requesting the metadata and the ask_channel call on our side
3216 * did not returned yet.
3217 */
3218 registry->metadata_key = metadata->key;
3219
d88aee68
DG
3220 /*
3221 * Ask the metadata channel creation to the consumer. The metadata object
3222 * will be created by the consumer and kept their. However, the stream is
3223 * never added or monitored until we do a first push metadata to the
3224 * consumer.
3225 */
7972aab2
DG
3226 ret = ust_consumer_ask_channel(ua_sess, metadata, consumer, socket,
3227 registry);
d88aee68 3228 if (ret < 0) {
f2a444f1
DG
3229 /* Nullify the metadata key so we don't try to close it later on. */
3230 registry->metadata_key = 0;
d88aee68
DG
3231 goto error_consumer;
3232 }
3233
3234 /*
3235 * The setup command will make the metadata stream be sent to the relayd,
3236 * if applicable, and the thread managing the metadatas. This is important
3237 * because after this point, if an error occurs, the only way the stream
3238 * can be deleted is to be monitored in the consumer.
3239 */
7972aab2 3240 ret = consumer_setup_metadata(socket, metadata->key);
ffe60014 3241 if (ret < 0) {
f2a444f1
DG
3242 /* Nullify the metadata key so we don't try to close it later on. */
3243 registry->metadata_key = 0;
d88aee68 3244 goto error_consumer;
5b4a0ec0
DG
3245 }
3246
7972aab2
DG